I DON'T UNDERSTAND! Use a system of equations to solve a word problem.
A. The sum of two numbers is -2, and their difference is 4. Find the two numbers.
B. One number is 2 less than a second number. Twice the second number is 14 less than 5 times the first. Find the two numbers.
C. A flat rectangular piece of aluminum has a perimeter of 64 inches. The length is 8 inches longer than the width. Find the width. Select one: A) 20 in. B) 32 in. C) 28 in. D) 12 in.

Hey there! I'm happy to help!

Let's create a basic rectangle with this length to width ratio.

Two sides are 3 and two of them have a length of 2. This would give us a perimeter (distance around) of 10.

We want to find a rectangle with a perimeter of 35 meters with this same ratio. What we can do is multiply all of the dimensions of our first rectangle by 3.5 (to get our perimeter of 10 to 35, we multiply by 3.5).

3×3.5=10.5

2×3.5=7

If we simplify 10.5:7, we have 3:2, and the perimeter of a rectangle with a length of 10.5 and a width of 7 would equal 35 meters.

Have a wonderful day! :D

Answer:

a is the right answer

Step-by-step explanation:

please give 5 star i need it

Answer:

x = -2

Step-by-step explanation:

​x−3x=2(4+x)

Distribute

x - 3x = 8 +2x

Combine like terms

-2x = 8+2x

Subtract 2x from each side

-2x-2x = 8+2x-2x

-4x = 8

Divide by -4

-4x/-4 = 8/-4

x = -2

Answer:

x-3x=2(4+x)

-2x=8+2x

-2x-2x=8

-4x=8

x=8/-4

x=-2

hope it helps budy x=2

mark me brainliest

Answer: 7.5

Step-by-step explanation:

All you have to do is divide the base/width by area.

Answer:

The answer is

Step-by-step explanation:

Area of a rectangle = length × width

From the question

Area = 90 in²

Width = 12 in

To find the length substitute these values into the formula and solve for the length

We have

90 = 12l

Divide both sides by 12

[tex] \frac{12l}{12} = \frac{90}{12} [/tex]

We have the final answer as

Hope this helps you

Answer: d) Neither of the answers are correct

Step-by-step explanation:

Law of Cosines: a² = b² + c² - 2bc · cos A

Note: The letters can be swapped but the letters on the outside must be the same.

Answer:

The correct answer is:

It is a continuous random variable. (B)

Step-by-step explanation:

Continuous random variables are variables that take on infinite possibility of values, hence the number of possible outcomes of a random variable cannot be counted. For instance, in this example, the amount of rainfall measured using a rain guage or a pluviometer has infinite possibilities of outcomes. it can either be 22.3 Liters, 20.1 Liters etc, up to infinity, in fact between 20 and 21 litres, there is an infinite possibility of outcomes.

Discrete random variables are variables that have a finite possibility of outcomes. the possibilities of occurrences can be counted. For example, if a coin is tossed, the coin can either land on its head or tail, hence there are two possibilities, making the variables discrete

The correct answer is:

It is a continuous random variable (B)

Step-by-step explanation:

Continuous Random Variables are variables that take on a number of possibilities of values that cannot be counted. The values have infinite possibilities. In this example, the height of a Giraffe measured in meters can be an unlimited possibility if values say, 10.5m, 15.22m 12.0m etc. The possibilities are endless.

Discrete Random variables are variables that take on a number of possibility of occurrences that can be counted. For instance, if a dice is rolled, the possibilities can either be a 1, 2, 3, 4, 5 or 6. There are six values that can be gotten, nothing in-between.

THANKS

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First set up the ratio 2/5 = 10/x where x is the number of girls.

Now, we can use cross-products to find the missing value.

So we have (2)(x) = (5)(10).

Simplifying, we have 2x = 50.

Dividing both sides by 2, we find that x = 25.

So there are 25 girls in the class if there are 10 boys.

Answer:

1 week= 7 days

number of days= 9

number of weeks= 1 week and 2 days

hope it helps :)

please mark it the brainliest!

Answer:

1 week and 2 days

Step-by-step explanation:

Answer:   A) a² = b² - w² + 2wx

Step-by-step explanation:

b² - (w - x)² = a² - x²

b² - (w² - 2wx + x²) = a² - x²

b² - w² + 2wx - x² = a² - x²

b² - w² + 2wx       = a²

Answer:

Option (B)

Step-by-step explanation:

Since all the four rays A, E, D and F are diverging from a point C in the different directions.

Therefore, sum of all the angles formed at a point C will be equal to 360°

m∠1 + m∠4 + m∠6 + m∠9 = 360°

25° + 34° + 146° + m∠9 = 360°

m∠9 = 360° - 205°

        = 155°

Therefore, measure of angle 9 is 155°.

Option (B) will be the correct option.

Answer:

Step-by-step explanation:

The general equation of a circle is expressed as x²+y²+2gx+2fy+c = 0 with centre at C (-g, -f).

Given the equation of the circles x²+y²−2x+4y+1  =0  and x²+y²+4x+2y+4  =0, to  get the centre of both circles, we will compare both equations with the general form of the equation above as shown;

For the circle with equation x²+y²−2x+4y+1  =0:

2gx = -2x

2g = -2

Divide both sides by 2:

2g/2 = -2/2

g = -1

Also, 2fy = 4y

2f = 4

f = 2

The centre of the circle is (-(-1), -2) = (1, -2)

For the circle with equation x²+y²+4x+2y+4  =0:

2gx = 4x

2g = 4

Divide both sides by 2:

2g/2 = 4/2

g = 2

Also, 2fy = 2y

2f = 2

f = 1

The centre of the circle is (-2, -1)

Next is to find the equation of a line containing the two centres (1, -2) and (-2.-1).

The standard equation of a line is expressed as y = mx+c where;

m is the slope

c is the intercept

Slope m = Δy/Δx = y₂-y₁/x₂-x₁

from both centres, x₁= 1, y₁= -2, x₂ = -2 and y₂ = -1

m = -1-(-2)/-2-1

m = -1+2/-3

m = -1/3

The slope of the line is -1/3

To get the intercept c, we will substitute any of the points and the slope into the equation of the line above.

Substituting the point (-2, -1) and slope of -1/3 into the equation y = mx+c

-1 = -1/3(-2)+c

-1 = 2/3+c

c = -1-2/3

c = -5/3

Finally, we will substitute m = -1/3 and c = 05/3 into the equation y = mx+c.

y = -1/3 x + (-5/3)

y = -x/3-5/3

Multiply through by 3

3y = -x-5

3y+x = -5

Hence the equation of the line containing the centers of the two circles is 3y+x = -5

If the three points all fall on the same straight line, then a triangle will not form. Instead, a line will. We call these points to be collinear.

If the points aren't collinear, then a triangle forms.

Answer:

No.

Step-by-step explanation:

The points may be in a straight line, and that doesn't form a triangle.

Answer:

Step-by-step explanation:

[tex] \sf{2(4x + 3)}[/tex]

Distribute 2 through the parentheses

⇒[tex] \sf{2 \times 4x + 2 \times 3}[/tex]

⇒[tex] \sf{8x + 6}[/tex]

Hope I helped!

Best regards!!

Answer:

your answer is 8x + 16

............

A)78°

135°+a° =180°

a°=45°

57°+x°+a°=180°

57°+x°+45°=180°

102°+x°=180°

x°=180°-102°

x°=78°

Answer:

[see below]

Step-by-step explanation:

A function is a relation where one domain value is assigned to exactly one range.

An x-value in a function must not repeat.

Hope this helps.

Answer: 11

Step-by-step explanation:

30 - 2(7+2)- 1        Distribute or  solve parentheses

30 - 14 -4 - 1  

30 - 19 = 11  

Answer: B. a = b .

First of all, let's think that a is equal to b.

Then, let's link up these two triangles.

Now, we have a parallelogram.

x+y = a+60

and 75 = b . So, a = b. Then, a is also = 75.

Now apply the basic triangle rule.

75+75+x=180 .. x = 30 degree.

and for the other triangle....

y+75+60=180 .. y= 45 degree...

Now, let's consider that we want to write a as b.

So, x+b+75=180 ...x+b=105

and..

y+b+60=180...y+b = 120..

Then, let's exit the b from these two equations.

-1/  x+b=105

    y+b=120

Finally, we found this: y-x =15

and we have already found y and x values.

y was 45 and x was 30 degree.

So when we put these two numbers into that equation y-x=15

we found the value of 15.

So, our answer is a=b.

Answer:

[tex]\huge \boxed{\mathrm{B.} \ a=b}[/tex]

Step-by-step explanation:

The two triangles form a parallelogram.

A parallelogram has opposite angles equal.

75 = b

Adjacent angles in a parallelogram are supplementary to one another.

They add up to 180 degrees.

a + 60 + 75 = 180

a + 135 = 180

Subtract 135 from both sides.

a = 75

Therefore, a = b.

Answer:

Length of the rectangular prism = 4 meters

But other possible values = (-5meters or - 9 meters)

Step-by-step explanation:

The volume of a rectangular prism = Length × Width × Height

From the question above,

Length = x meters

Width = x - 1 meters

Height = x + 11 meters

Volume of the Rectangular prism = 180 cubic meters

Hence,

(x) × (x - 1) × (x + 11) = 180

We expand the brackets

(x)(x - 1) (x + 11) = 180

x² - x(x + 11) = 180

x² (x + 11) - x(x + 11) = 180

x³ + 11x² - x² + 11x =180

x³ +10x² - 11x = 180

x³ + 10x² - 11x -180 = 0

The above is a polynomial

We solve this polynomial to find x

x³ + 10x² - 11x -180 = 0

(x - 4)(x + 5) (x + 9) = 0

x - 4 = 0

x = 4

x + 5 = 0

x = -5

x + 9 = 0

x = -9

We are asked to find the various values for the length hence,

From the above question, we are told that

Length = x meters

Therefore, the length of this rectangular prism = 4 meters or -5 meters or -9 meters.

Answer:

(1, 4)

Step-by-step explanation:

[tex](0,-4)[/tex] fits the linear equation perfectly.

Hope this helps.

Answer:

the y-intercept is the point (0, -4) on the plane

Step-by-step explanation:

In order to find the y-intercept, write the equation in "slope intercept form"  solving for "y":

[tex]2\,y=x-8\\y=\frac{x-8}{2} \\y=\frac{x}{2} -\frac{8}{2} \\y=\frac{x}{2} -4[/tex]

Recall now that the y-intercept is the value at which the line crosses the y-axis (when x = 0), therefore:

[tex]y=\frac{x}{2} -4\\y=\frac{0}{2} -4\\y=-4[/tex]

So the y-intercept is the point (0, -4) on the plane.

Answer:

x = 1/25

Step-by-step explanation:

2/5x+1/x=35

[tex]2/5x+1/x=35[/tex]

taking 1/x common

[tex]1/x(2/5+1)=35[/tex]

[tex](2+5)/5=35x\\7/5 = 35x\\x = 7/(5*35) = 1/(5*5) = 1/25[/tex]

Thus, value of x is 1/25

Answer:

0.185185185185185185.........

Step-by-step explanation:

i used a  calculator, to the nearst tenth is 0.18 to the nearest 100th is 0.185 also the 185 is repeating so u put a line over the numbers 185

Answer:

3 ÷ 162 = 0.01851851851

If you meant 162 ÷ 3 it is 54

If niether of the two answers above didnt answer your question, then sorry

Answer:

False the conjugate of 2+5i is 2-5i .

Step-by-step explanation:

Hope it will help you :)

Answer: 300%

Step-by-step explanation:

percent of increase: new/old×100%-100%

Since it is percent of increase, you need to subtract the original percent (100%) from the current percent.

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

new (current)=2000

old (original)=500

 new/old×100%-100%

=2000/500×100%-100%

=4×100%-100%

=400%-100%

=300%

Hope this helps!! :)

Please let me know if you have any question or need further explanation

Answer:

x = -4

Step-by-step explanation:

This vertical line is x = -4.  That's all we need here.

Answer:

There is sufficient evidence that there is linear  correlation between two variable

Step-by-step explanation:

From the question we are told

   The significance level is  [tex]\alpha = 0.01[/tex]

   The critical value  is  [tex]a = 0.590[/tex]

   The  test statistics is  [tex]r = 0.591[/tex](linear correlation coefficient )

Now  from the data given in the value we see that

     [tex]r > a[/tex] so  the null hypothesis is rejected

Hence the conclusion is that there is  sufficient evidence that there is linear   correlation between two variable  

Answer:

K=3.333

Step-by-step explanation:

-3=9(5-2k)/5

-3=45-18k/5

-15=45-18k

18k=60

K=60/18

K=3.3333

Answer:

Calculated z= 3.515

The Z∝/2 = ±1.96  for ∝= 0.05

The Z∝/2 = ± 2.58  for ∝= 0.01

Yes the company claims valid at a level of significance of 0.05 and 0.01

Step-by-step explanation:

Here p1= 70% = 0.7

p2= 20/45= 0.444   q= 1-p= 1-.444= 0.56

The level of significance is 0.05 and 0.01

The null and alternative hypotheses are

H0; p1= p2                Ha: p1≠p2

The test statistic used here is

Z= p1-p2/ √pq/n

Z= 0.7-0.44/ √ 0.44*0.56/45

z= 0.26/ √0.2464/45

z= 3.515

The Z∝/2 = ±1.96  for ∝= 0.05

The Z∝/2 = ± 2.58  for ∝= 0.01

For the significance level 0.05 reject null hypothesis

For the significance level 0.01 reject null hypothesis

Yes the company claims valid at a level of significance of 0.05 and 0.01

Answer:

1. Yes, there is sufficient evidence to support the claim that student cars are older than faculty cars.

2. The 98% confidence interval for the difference between the two population means is [1.432 years, 3.968 years].

Step-by-step explanation:

We are given that randomly selected 110 student cars to have ages with a mean of 8 years and a standard deviation of 3.6 years, while randomly selected 75 faculty cars to have ages with a mean of 5.3 years and a standard deviation of 3.7 years.

Let [tex]\mu_1[/tex] = mean age of student cars.

[tex]\mu_2[/tex]   = mean age of faculty cars.

So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu_1 \leq \mu_2[/tex]      {means that the student cars are younger than or equal to faculty cars}

Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu_1>\mu_2[/tex]      {means that the student cars are older than faculty cars}

(1) The test statistics that will be used here is Two-sample t-test statistics because we don't know about the population standard deviations;

                             T.S.  =  [tex]\frac{(\bar X_1-\bar X_2)-(\mu_1-\mu_2)} {s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }[/tex]   ~   [tex]t_n_1_+_n_2_-_2[/tex]

where, [tex]\bar X_1[/tex] = sample mean age of student cars = 8 years

[tex]\bar X_2[/tex] = sample mean age of faculty cars = 5.3 years

[tex]s_1[/tex] = sample standard deviation of student cars = 3.6 years

[tex]s_2[/tex] = sample standard deviation of student cars = 3.7 years

[tex]n_1[/tex] = sample of student cars = 110

[tex]n_2[/tex] = sample of faculty cars = 75

Also, [tex]s_p=\sqrt{\frac{(n_1-1)\times s_1^{2}+(n_2-1)\times s_2^{2} }{n_1+n_2-2} }[/tex]  = [tex]\sqrt{\frac{(110-1)\times 3.6^{2}+(75-1)\times 3.7^{2} }{110+75-2} }[/tex]  = 3.641

So, the test statistics =  [tex]\frac{(8-5.3)-(0)} {3.641 \times \sqrt{\frac{1}{110}+\frac{1}{75} } }[/tex]  ~ [tex]t_1_8_3[/tex]

                                     =  4.952    

The value of t-test statistics is 4.952.

Since the value of our test statistics is more than the critical value of t, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region.

Therefore, we support the claim that student cars are older than faculty cars.

(2) The 98% confidence interval for the difference between the two population means ([tex]\mu_1-\mu_2[/tex]) is given by;

98% C.I. for ([tex]\mu_1-\mu_2[/tex]) = [tex](\bar X_1-\bar X_2) \pm (t_(_\frac{\alpha}{2}_) \times s_p \times \sqrt{\frac{1}{n_1}+\frac{1}{n_2} })[/tex]

                                 = [tex](8-5.3) \pm (2.326 \times 3.641 \times \sqrt{\frac{1}{110}+\frac{1}{75} })[/tex]

                                 = [tex][2.7 \pm 1.268][/tex]

                                 = [1.432, 3.968]

Here, the critical value of t at a 1% level of significance is 2.326.

Hence, the 98% confidence interval for the difference between the two population means is [1.432 years, 3.968 years].

Answer:

The number of ways to distribute 30 batteries among the six different types is 33,649.

Step-by-step explanation:

It is provided that a camera shop stocks six different types of batteries, one of which is type A7b.

Also, the camera shop has only twelve A7b batteries but at least 30 of each of the other types.

Combinations would be used to determine the number of ways to distribute 30 batteries among the six different types. Here repetition is allowed.

[tex]C(n+r-1, r)={n+r-1\choose r}=\frac{(n+r-1)!}{r!(n-1)!}[/tex]

The number of A7b batteries is 12.

Then the number of ways to distribute 30 batteries among the six different types is:

[tex]C(n+(r-k)-1, (r-k))={n+(r-k)-1\choose (r-k)}=\frac{(n+(r-k)-1)!}{(r-k)!(n-1)!}[/tex]

The number of ways is:

[tex]C(n+(r-k)-1, (r-k))={n+(r-k)-1\choose (r-k)}[/tex]

                                          [tex]=\frac{(n+(r-k)-1)!}{(r-k)!(n-1)!}\\\\=\frac{(6+(30-12)-1)!}{(30-12)!\times (6-1)!}\\\\=\frac{23!}{18!\times 5!}\\\\=\frac{23\times 22\times 21\times 20\times 19\times 18!}{18!\times 5!}\\\\=\frac{23\times 22\times 21\times 20\times 19}{ 5!}\\\\=33649[/tex]

Thus, the number of ways to distribute 30 batteries among the six different types is 33,649.

Answer:

− 4 y  − 7

Step-by-step explanation:

Remove parentheses.

− 4 y − 4 − 3

Subtract  3  from  − 4

− 4 y  −  7

.