A boat takes twice as long to travel 5 km upstream as it does travel 3km downstream in a river that flows at a rate of 2 kph. At what speed does the boat travel in still water?

Answers

Answer 1

Answer: 22 kph

Step-by-step explanation:

distance (d) = rate (r) x time (t)

UPSTREAM: d = 5 km,   r = *x - y,  y = 2 kph,   t = 2t

DOWNSTREAM: d = 3 k,  r = *x + y,   y = 2 kph,   t = t

*x is the speed in still water and y is the current of the water.

Upstream equation:       5 = 2t(x - 2)   -->    [tex]\dfrac{5}{2(x-2)}=t[/tex]

Downstream equation:  3 = t(x + 2)     -->    [tex]\dfrac{3}{x+2}=t[/tex]

Set the equations equal to each other to solve for x:

[tex]\dfrac{5}{2(x-2)}=\dfrac{3}{x+2}\\\\\\\text{Cross multiply:}\\5(x+2)=3\cdot2(x-2)\\\\\text{Distribute:}\\5x+10=6x-12\\\\\text{Isolate x:}\\10=x-12\\22=x[/tex]

                               

Answer 2

Step-by-step explanation:

Step-by-step explanation:

distance (d) = rate (r) x time (t)

UPSTREAM: d = 5 km, r = *x - y, y = 2 kph, t = 2t

DOWNSTREAM: d = 3 k, r = *x + y, y = 2 kph, t = t

*x is the speed in still water and y is the current of the water.

Upstream equation: 5 = 2t(x - 2) --> \dfrac{5}{2(x-2)}=t

2(x−2)

5

=t

Downstream equation: 3 = t(x + 2) --> \dfrac{3}{x+2}=t

x+2

3

=t

Set the equations equal to each other to solve for x:

\begin{gathered}\dfrac{5}{2(x-2)}=\dfrac{3}{x+2}\\\\\\\text{Cross multiply:}\\5(x+2)=3\cdot2(x-2)\\\\\text{Distribute:}\\5x+10=6x-12\\\\\text{Isolate x:}\\10=x-12\\22=x\end{gathered}

2(x−2)

5

=

x+2

3

Cross multiply:

5(x+2)=3⋅2(x−2)

Distribute:

5x+10=6x−12

Isolate x:

10=x−12

22=x


Related Questions

I need help on this problem. (-5)^5/(-5)^-6

Answers

Answer: (-5)¹¹ of (-5)^11

Step-by-step explanation:

Since the base of the two exponents are teh same at -5, we can subtract the exponents.

5-(-6)=11

Now, we know that the new exponent will be 11, with the base staying the same.

Evaluate the expression when x = 5 and z= 7.
5z +x
Simplify your answer as much as possible.

Answers

40
Reason 5(7)+(5)=40

Answer:

12

Step-by-step explanation:

We are given the expression:

[tex]\frac{5z+x^2}{x}[/tex]

and asked to evaluate when x= 5 and z=7. Therefore, we must substitute 5 for x and z for 7.

[tex]\frac{(5(7)+(5)^2)}{5}[/tex]

Solve according to PEMDAS: Parentheses, Exponents, Multiplication, Division, Addition, Subtraction.

First, evaluate the exponent.

(5)²= 5*5= 25

[tex]\frac{(5(7)+25)}{5}[/tex]

Next, multiply 5 and 7.

5*7=35

[tex]\frac{(35+25)}{5}[/tex]

Next, add 35 and 25.

25+25=60

[tex]\frac{60}{5}[/tex]

Finally, divide 60 by 5.

[tex]12[/tex]

The expression (5z+x²)/x when x=5 and z=7 is 12.

Figure A is a scale image of Figure B.
27
Figure A
Figure B
45
35
What is the value of x?

Answers

Greetings from Brasil...

According to the statement, one figure is scaled in relation to another, so we can apply similarity to polygons.....

So

BIG/small = BIG/small

or

small/BIG = small/BIG

27/X = 45/35

OR

35/45 = X/27

27/X = 45/35

45X = 27·35

45X = 945

X = 945/45

X = 21

The record high temperature in Alabama is 112f and the record low temperature is -27f. What is the difference between the highest and lowest temperature? A. 139 degrees B. 27 degrees C. 85 degrees D. 112 degrees

Answers

Answer:

(A) 139°

Step-by-step explanation:

What we are trying to find here is the distance between -27 and 112.

To do this, we have to think of it as a number line.

The distance from -27 to 0 is 27 units, and the distance from 0 to 112 is 112 units.

So the total distance is [tex]112+27=139[/tex]

Hope this helped!

Find m∠PQR. A. 81 B. 90 C. 77 D. 72

Answers

Answer: D. 72

Work Shown:

Angle PQR = (far arc - near arc)/2

Angle PQR = ( (major arc PR) - (minor arc PR) )/2

Angle PQR = ( (2x+252) - (2x+108) )/2

Angle PQR = 144/2

Angle PQR = 72

Notice how we didn't need to find the value of x at all.

solve the equation -3+(1) −3+(1)

Answers

Answer:

-4

Step-by-step explanation:

you can just plug this into a calculator.

OR you could take -3+1 and get -2 and then subtract that from 2 (-3+1=2) and then you get -4

Answer:

-4

Step-by-step explanation:

-3 + (+1)= -2

2(-3 + (+1)) = -4

The area of a compact disc is 78.53 square centimeters. What is the radius of the disc? Use pi = 3.14

Answers

Answer:

r = 5 cm

Step-by-step explanation:

A = πr²

78.53 = (3.14)r²

divide by 3.14

25 = r²

r = ±5

r = 5

Read the table. 1/2 = 2 gallons 1 = 4 gallons 1 1/2 = 6 gallons. If this goes on. how much gallons is 6 1/2?

Answers

Answer:

24 1/2

Step-by-step explanation:

Every 1/2 is 2 gallons.

1/2 x 2 gallons = 4 gallons.

The whole number in 6 1/2 is 6.

1 x 6 = 6.

Now, we multiply 6 by 4 because each 1 = 4 gallons.

6 x 4 = 24.

There is still an 1/2 left in 6 1/2.

You add that.

Your answer is 24 1/2.

Hope this helps you!

You have —1 ounce of whole wheat grains. How many more ounces do you need to 8
make the recipe?

Answers

idek

-=-=-=--=-==-=-=-=-=-=-=-=-=-=-=-===========-----------------==============================================------------------------------------------------------====================================-----------==================--===================================--------------------------------------------------==========--------------------========----------------------------------------------------================-------------=====-=-=-=-=-==-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

midpoint of the segment with endpoints A(-5, -2) and B(-7, 6).

Answers

(-6,2)

Inbox me on fb for more help with math same name as my brainly

Answer:

(-6,2)

Step-by-step explanation:

step by step explanation pls?

Answers

Answer:

x = 34

Step-by-step explanation:

x/3  - 7/3 = 9

Combine like terms

(x-7)/3 = 9

Multiply each side by 3

(x-7)/3 * 3 = 9*3

x-7 = 27

Add 7 to each side

x-7+7 = 27+7

x = 34

what is the difference between -8 to the power of 2 and (-8) to the power of 2?

Answers

Answer:

0

because -8 powered 2 and -8 powered 2 is same. 64-64=0

Step-by-step explanation:

Graph the function and its parent function. Then describe the
transformation.
g(x) = 1/3x^2

Answers

Answer: find the answer in the explanation

Step-by-step explanation:

Given the function and its parent function, to describe the

transformation of g(x) = 1/3x^2

First sketch the graph of the parent function which is g(x) = x^2

For every value of x, g(x) will take the value it would have had at kx, that is, the graph of g(x) = x^2 is stretched by a factor of 1/3 in the x - direction.

Find the attached files for the graph and solution

Pls help answer ASAP I will give Brainlyist

Answers

Answer:

Letter B because it is less than. < is less than

Step-by-step explanation:

Answer:

B

Step-by-step explanation:

c < 27.50

The sign < means less than.

Plug the numbers in and you've got:

The cost is less than $27.50

Good luck mate :)

PLZ HELP ME 100 POINT AND BRAINEST Solve the Quadratic Equation X^2 = -8x -7
A. 7, -1
B. -1, -7
C. 8, 1
D. 7,1
E. -8, -1

Answers

Answer:

B

Introduction:

Given equation: [tex]x^2 = -8x -7[/tex]

To solve the quadratic equation, we will need to set one side of the equation equal to 0. This can be done by subtracting x² on both sides.

[tex]\implies x^2 - x^2= -8x -7 - x^2[/tex]

[tex]\implies 0= -8x -7 - x^2[/tex]

To further simplify, we can factor -1 from the expression on the R.H.S. Then, we can cancel the -1 since there is a 0 on the other side.

[tex]\implies 0= -1(8x + 7 + x^2)[/tex]

[tex]\implies 0= 8x + 7 + x^2 = x^2 + 8x + 7[/tex]

Finally, factor the expression on the right hand side.

Factoring a quadratic equation can be done in 2 ways.

1) Splitting method

In this method, we split the middle term into two suitable terms. The suitable terms must follow two conditions.

The product of the suitable terms must be equal to the product of the first and last terms of the expression. The sum of the suitable terms must be equal the middle term.

Then, we factor the first two terms of the expression and the last two terms of the expression. Eventually, we will get a common expression. So, we can further factorize to get a product of two expressions.

However, this method follows a condition. If the middle term cannot be split into two suitable terms, then the second method should be followed to determine a solution. 2) The Quadratic Formula

In this method, we will compare our equation with the standard form equation to determine the a, b, and c variables. Then, we plug the variables into the formula and simplify to get the roots (solutions).

[tex]\text{Quadratic Formula:} \ \dfrac{-b\ \± \sqrt{b^{2} - 4ac} }{2a}[/tex]

We can use any method to solve for the roots. First, let us check whether the middle term could be split into two suitable terms such that those terms could meet the criteria stated above.

-----------------------------------------------------------------------------------------------------

Solving for x using the splitting method

We can see that 8x is the middle term and it can be split into the sum of 7x and x. The product of the (middle term) coefficients is 7. The product of the coefficients (first and last terms) is also 7. Since both products match, we can use the splitting method to factorize the expression.

[tex]\implies 0= x^2 + 8x+ 7[/tex]

[tex]\implies 0= x^2 + x + 7x+ 7[/tex]

Now, factor the first two terms and the last two terms separately.

[tex]\implies 0= x^2 + x + 7x+ 7[/tex]

[tex]\implies 0= x(x + 1) + 7(x+ 1)[/tex]

We can see a common expression. Finally, let us factor the common expression to get a product of two expressions.

[tex]\implies 0= (x + 7)(x + 1)[/tex]

Since the factorized expression equals to 0, we can set each expression (inside the parentheses) equal to 0.

[tex]\implies x + 7 = 0; x + 1 = 0[/tex]

[tex]\implies x = -7; x = -1[/tex]

Solving for x using the Quadratic formula

Now, let us try to solve using the Quadratic formula.

[tex]0= x^2 + 8x+ 7[/tex]

Tip: Standard form: 0 = ax² + bx + c

Comparing both equations will allow us to determine the a, b, c variables.

⇒ a = 1; b = 8; c = 7

Now, let us plug these values into the quadratic formula and simplify.

[tex]\implies \dfrac{-b\ \± \sqrt{b^{2} - 4ac} }{2a}[/tex]

[tex]\implies \dfrac{-8\ \± \sqrt{8^{2} - 4(1)(7)} }{2(1)}[/tex]

[tex]\implies \dfrac{-8\ \± \sqrt{64 - 28} }{2}[/tex]

[tex]\implies \dfrac{-8\ \± \sqrt{36}}{2} = \dfrac{-8\± 6}{2} = \dfrac{-8 + 6}{2},\ \dfrac{-8 - 6}{2} = \dfrac{-2}{2} ,\ \dfrac{-14}{2} = -1 , -7 \ \text{(B)}[/tex]

Therefore, in both methods, the answer is -1, -7 (B).

Learn more about quadratic formula: brainly.com/question/22364785

Learn more about splitting method: brainly.com/question/13874704

Which equation is equivalent to 7w – 1 = –15?

A: 1 - 7w = -15
B: 7w = -15 + 1
C: 7w = –15 – 1
D: 7w = 15 - 1

Answers

Answer:

i believe the answer is A

Step-by-step explanation:

In each expression below identify the coefficient constant and variable

Answers

Answer:

The expression is missing in the question.

The expression is 4x +450

The variable is x and the coefficient is 4

Step-by-step explanation:

In an expression, a variable is a quantity which is not fixed value and can be of any arbitrary value. A variable is the unknown in the expression. In any expression, the variable are represented by alphabets such as a, b, c, x, y or z etc.

The numeric quantity which lies in the front of a variable is known as a coefficient. It can be any numeric values. For example, 9x --- here 9 is the coefficient of variable x, 4x -- here 4 is the coefficient.

A dealer sold a painting for $800. She made a profit of 25% on the price she paid for it. Calculate the price she paid for the painting.

Answers

She paid $640 for the painting

Step-by-step explanation:

her selling price SP = 800

CP+25%of CP = 800

1.25CP=800

CP=640

Answer:

$640

Step-by-step explanation:

paint sold for $800

profit 25%

the price she paid for the painting = $800 / 1.25 = $640

Show that the statement is true. If DF has endpoints D(-1,8) and E(3,-2), then the midpoint M of DE lies
I
in Quadrant I.
The midpoint M is
and the y-coordinate is (select)
). M lies in (select)
since the x-coordinate is (select) v

Answers

please help me with my homework

what is the slope of the line shown below? (1,-4) (2,2)

Answers

Your question has been heard loud and clear.

Slope formula when two points are given= y2-y1/x2-x1

Here y2= 2

X2=2

Y1= -4

X1= -1

= 2-(-4)/2-(-1)= 2

Slope of line= 2

Thank you.

Answer:

[tex]\huge \boxed{\mathrm{B. \ 2}}[/tex]

Step-by-step explanation:

The line crosses two points.

The two points are (-1, -4) and (2, 2).

The slope of a line can be found through two points.

[tex]\displaystyle \sf slope = \frac{rise}{run}[/tex]

[tex]\displaystyle m=\frac{y_2-y_1}{x_2-x_1}[/tex]

[tex]y_2=2 \\ y_1 = -4 \\ x_2=2 \\ x_1=-1[/tex]

Plug in the values and evaluate.

[tex]\displaystyle m=\frac{2-(-4)}{2-(-1)}[/tex]

[tex]\displaystyle m=\frac{2+4}{2+1}[/tex]

[tex]\displaystyle m=\frac{6}{3}[/tex]

[tex]m=2[/tex]

The slope of the line is 2.

A contractor purchases 7 dozen pairs of padded work gloves for ​$102.48. She incorrectly calculates the unit price as ​$14.64 per pair for the expense report. What is the correct unit​ price? What is the​ error?

Answers

Answer:

The correct unit price can be calculated by dividing the total price paid by 84 that was the number of pairs of padded work gloves that were bought:

$102.48/84=$1.22

The correct unit price is $1.22.

-The error is that the person calculated the unit price by dividing the total price paid by 7 but the statement indicates that the contractor purchased 7 dozen pairs, which means: 7*12= 84. According to this, the contractor purchased 84 pairs of padded work gloves.

please help me on this

Answers

Answer:

Step-by-step explanation:

coordinate of O(2,1),Y(3,-2),T(-3,-3)

let the reflected points are O',Y',T'

distance of O from y=2 is 1 unit.

∴ ordinate of O' =1+2(1)=3

or O' is (2,3)

distance of Y from y=2 is2+2=4

ordinate of Y'=-2+2(4)=6

so coordinate of Y' is (3,6)

distance of T from y=2 is (2+3)=5

so ordinate of T' =-3+2(5)=7

coordinate of T' is(-3,7)

given the relation y=x+2, if the input is 3, what is the output

Answers

Answer:

The output is 5

Step-by-step explanation:

y=x+2,

Let x =3

y = 3+2

y = 5

The output is 5

Answer:

5

Step-by-step explanation:

We are given the relation:

y=x+2

The input is also called "x", and the output is also known as "y". We want to find the output, or y, when x is equal to 3.

Therefore, we must substitute 3 in for x and solve.

y= x+2 at x=3

y=3+2

Add 3 and 2.

y=5

If the relation is y=x+2 and the input is 3, then the output is 5.

8. Laurenpacksanorderofblocksin 2 crates and 7 stacks. How many blocks does Lauren pack?

Answers

Answer:

14

Step-by-step explanation:

(multiply 2by7)

2×7

=14

What equation represents a population of 300 animals at the crease and an annual rate of 23%

Answers

Answer:

300 + 69x

Step-by-step explanation:

Given initial population of animals = 300 animals

If the population increases by 23% annualy, yearly increment will be expressed as:

Yearly increment = 23% of 300

Yearly increment = 0.23*300

Yearly increment for = 69

Let the total number of years of be x

Increment after x years = 69x

Increase in population of animals after x years with an annual rate of 23% = Initial population + Increment after x years

= 300 + 69x

Hence, the equation represents a population of 300 animals at the increase and an annual rate of 23% is expressed as 300 + 69x

ifran manages a coffee shop.
The rest of the question is in the screen shot

Answers

Answer:

230 capsules.

Step-by-step explanation:

The following data were obtained from the question:

Taste >>>>>>>>>>> Frequency

Volluto >>>>>>>>>> 12

Livanto >>>>>>>>>> 7

Ristretto >>>>>>>>> 23

Cosi >>>>>>>>>>>> 3

Other >>>>>>>>>>> 5

Next, we shall determine the total frequency.

This is illustrated below:

Total frequency = 12 + 7 + 23 + 3 + 5

Total frequency = 50

Finally, we shall determine the number of Ristretto in 500 capsules.

This can be obtained as follow:

Number of Ristretto = Frequency of Ristretto /total frequency x total capsule

Frequency of Ristretto = 23

Total frequency = 50

Total capsule = 500

Number of Ristretto = 23/50 x 500

Number of Ristretto = 23 x 10

Number of Ristretto = 230.

Therefore, the number of Ristretto in the 500 capsules is 230.

What is the value of
3 - x if x = 6?

Answers

Answer:

-3

Step-by-step explanation:

3-x if x=6

3-6

-3

Hope this helps ;) ❤❤❤

Answer: -3

Step-by-step explanation: In this case, we are given that x = 6.

So we have 3 - 6 which is -3.

(6x3 + 3x² + 3) + (2x - 5x + 1)
the sum is?

Answers

Answer:8x^3 + 3x^2 - 5x + 4 is the answer.

Step-by-step explanation:

(6x^3 + 3x² + 3) + (2x^3 - 5x + 1)

6x^3 + 2x^3 = 8x^3

3x^2 + 0 = 3x^2

-5x + 0 = -5x

3 + 1 = 4

8x^3 + 3x^2 - 5x + 4 is the answer because you have to put all the terms that were solved together. This will lead to 8x^3 + 3x^2 - 5x + 4. And, standard form is ax^2 + bx + c. So, 8x^3 + 3x^2 - 5x + 4 is the answer.

8x^3 + 3x^2 - 5x + 4

Hope this helped,

Kavitha

Answer:

= 8x³ + 3x² - 5x + 4

Step-by-step explanation:

(6x³ + 3x² + 3) + (2x³ - 5x + 1)

= 6x³ + 3x² + 3 + 2x³ - 5x + 1    remove parentheses

= 6x³ + 2x³ + 3x² - 5x + 1          group like terms

= 8x³ + 3x² - 5x + 3 + 1              add similar elements

= 8x³ + 3x² - 5x + 4

A rectangle is 10 inches smaller than it is wide. The perimeter of the rectangle is 80 inches. Find the length and the width of the rectangle.​

Answers

Answer:

l = 15 and w = 25

Step-by-step explanation:

[tex]l - w = - 10[/tex]

[tex]l + w = 40[/tex]

Adding both equations

[tex]2l = 30[/tex]

[tex]l = 15[/tex]

subtracting both equation

[tex]2w = 50[/tex]

[tex]w = 25[/tex]

Hope it helps..........

BRAINLIEST PLEASE

Answer:

Length=30 Width=10

Step-by-step explanation:

Riley is preheating her oven before using it to bake. The initial temperature of the oven is 65° and the temperature will increase at a rate of 10° per minute after being turned on. What is the temperature of the oven 6 minutes after being turned on? What is the temperature of the oven t minutes after being turned on? ​

Answers

Answer:

After 6 minutes, the oven temperature will be: [tex]125^o[/tex]

Step-by-step explanation:

If the increase in temperature is [tex]10^o[/tex] per minute, then in 6 minutes, the increase in temperature would be [tex]6\,*\,10^o=60^o[/tex], therefore, since the initial temperature of the oven was [tex]65^o[/tex], its temperature after 6 minutes would be:

[tex]65^o+60^o=125^o[/tex]

Other Questions
Simplify: 2 - 6x + 8x3 + 1 = 23 Eloise scored a total of 268 points during the basketball season. Of her total points, l points came from left handed shots. She scored 225 points from right handed shots write an equation to describe the situation and find the value of l for left handed shots Calculate the density of a rod of metal in g/cm3, with a mass of 9.58g, a diameter of 8 mm and a height of 3.5cm Prompt: A psychology graduate student conducted a study at the entrance to a football game at the university. The entrance was specifically for students who made the Dean's List for academic achievement during the previous semester. Some students arrived to watch the game by themselves, while others arrived in a group. As they arrived, the graduate student asked half of the students to record their attendance on an attendance sheet. The remaining half were allowed to enter the game without recording their attendance. The graduate student told every student to take one soda and one hamburger from a concessions table sponsored by the Dean's Office. She then returned to the sign-in table out of sight of the concessions. This gave the students the opportunity to take additional food. The graduate student measured the percentage of students who took additional free food. Her hypotheses were that students would take more food when they were alone and when they were not asked to sign in. The results are shown in the graph below; assume all differences are significant. Questions: Identify each of the following in this study: Control group, Confounding variable, Independent variable, and provide an operational definition of the dependent variable. Explain how the data support or do not support each of the hypotheses. Explain why the findings cannot be generalized to all students Explain why the study is not a naturalistic observation. Linda scored a total of 265 points in mathematics, physics and English. She scored 7 more marks in mathematics than in English and she scored 5 more marks in physics than in mathematics. Find her scores in all three subjects. Which statement best reveals how Namjil and his wife view the magical horse? Both Namjil and his wife believe the horse will solve all their problems. Namjil uses the horse only for work purposes; his wife adores the horse like a pet. Namjil cherishes the horse; his wife wishes the horse would stop taking Namjil away from her. Namjil hopes the horse will make him famous; his wife hopes the horse will make them rich. If (5 t the power of 4)m = 5 to the power of 12, what is the value of m? (4 points) 2 3 5 8 Mishoe Corporation has provided the following contribution format income statement. Assume that the following information is within the relevant range. Sales (1,000 units) $ 50,000 Variable expenses 32,500 Contribution margin 17,500 Fixed expenses 12,250 Net operating income $ 5,250 The break-even point in unit sales is closest to:______ a) 0 units b) 895 units c) 700 units or 650 what is the solution to 6x 8 > 4x + 26 PLEASE HELP!!!!!!!!!! what is john lewis legacy what is the net force on an object that is experiencing a force of 25 N north, a force of 25 N south, a force of 50 N to the east and a force of 45 N to th west? Elena drank 3 liters of water yesterday. Jada drank 34 times as much water as Elena. Lin drank twice as much water as Jada. Did Jada drink more or less water than Elena? Explain how you know. Did Lin drink more or less water than Elena? Explain how you know. Which of the following are protected freedoms based on the first amendment?speechpresspetitionAll of the aboveA & B only A firearm safety: _________a. can fail when least expected due to wear or other factors b. cannot unknowingly be bumped from the safe position c. is a device that blocks the cartridge from entering the chamber d. can be relied on at all times to protect against accidental shooting An amplified recording of the waves of electrical activity that sweep across the surface of the brain is called a(n):_______ I will give you 30 points ? Need it quick please Which equation can be used to find the length of AC?A10 in.b40CBCUO (10)sin(40) = ACO (10)cos(40) = AC1= ACsin(40)10cos(40= AC In the scientific method, how is a hypothesis tested? By becoming a theory By doing minimal research By experimentation and observation By disputing the results of other scientists In a camp, 16.1 kg of rice is cooked each week. Find the quantity of rice cooked in the month of October.