Hello!
x² + 6x + 1 = 0 <=>
<=> x = -6±√6²-4×1×1/2×1 <=>
<=> x = -6±√36-4/2 <=>
<=> x = -6±√32/2 <=>
<=> x = -6±2²√2/2 <=>
<=> x = -6±4√2/2 <=>
<=> x = -6+4√2/2 <=>
and
<=> x = -6-4√2/2 <=>
<=> x = -3+2√2 <=>
and
<=> x = -3-2√2 <=>
x1 = -3-2√2 and x2 = -3+2√2
Good luck! :)
HELP PLEASE! I tried everything from multiplying, dividing, adding, and subtracting but still no correct answer. Can someone please help me out here?
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Explanation:
There are a few ways to do this.
One method involves drawing a horizontal line to form three rectangles as show below. Note the labels A,B,C.
Rectangle A in the upper left corner has area of base*height = 6*7 = 42 square miles. I'll let A = 42 since we'll use it later.Rectangle B is 20 miles across horizontally (base) and 2 miles tall vertically (height). The 2 miles is from 9-7 = 2. The area of rectangle B is 20*2 = 40 square miles. Let B = 40.Then finally, C = 28 because rectangle C is 4 miles across and 7 miles tall, so 4*7 = 28.Add up those three sub areas found: A+B+C = 42+40+28 = 110 square miles
----------------
There are other methods you could do. A second method is to draw two vertical lines to form 3 other rectangles, then add up the sub areas to get 110.
A third method is to draw a horizontal line across the top to form one large rectangle (20 mi by 9 mi) and subtract off the area of the 7 mi by 10 mi inner rectangle (the empty space), so you'd say 20*9 - 7*10 = 180-70 = 110
QUESTION 1
Express the following ratios as fractions.
4:6
Answer:
should just be 4/6 or 2/3 simplified lol
Step-by-step explanation:
ratios and fractions are very similar, just pronounced differently. 4:6 is read as "four to fix" while 4/6 is read as "four sixths". only difference is the punctuation
Question 1 of 12, Step 1 of 1
0/17
Correct
Two planes, which are 2800 miles apart, fly toward each other. Their speeds differ by 50 mph. If they pass each other in 4 hours, what is the sspeed of each?
Keypad
Answer:
325 and 375 mph
Step-by-step explanation:
Given :
Distance between plane A and B = 2800
Recall :
Distance = speed * time
Let speed of A = v1
Speed of B = v2
v1 = v2 + 50
Time taken = 4 hours
Distance = speed * time
Total distance = 2800
2800 = v1 * 4 + v2 * 4
2800 = (4v1) + (4v2)
2800 = 4(v2+50) + 4v2
2800 = 4v2 + 200 + 4v2
2800 = 8v2 + 200
2800 - 200 = 8v2
2600 = 8v2
v2 = 2600/8
v2 = 325 mph
v1 = v2 + 50
v1 = 325 + 50
v1 = 375 mph
can a horizontal line be written in slope intercept form
Answer:
it can be in point intercept form
Step-by-step explanation:
Answer:
it can be point intercept from
The function f(x) is shown below.
х
-6
-3
f(x)
1
2
5
3
Coon
0
If g(x) is the inverse of f(x), what is the value of f(g(2))?
-6
оооо
5
Answer:
[tex]f(g(2)) = 2[/tex]
Step-by-step explanation:
Given
[tex]x \to f(x)[/tex]
[tex]-6 \to 1[/tex]
[tex]-3 \to 2[/tex]
[tex]g(x) = f^{-1}(x)[/tex] --- inverse
Required
[tex]f(g(2))[/tex]
For two functions f(x) and g(x) where f(x) and g(x)are inverse;
[tex]f(g(x)) = x[/tex]
So, by comparison:
[tex]f(g(2)) = 2[/tex]
The population of a bacteria colony is growing exponentially, doubling every 6 hours. If there are 150 bacteria currently present, how many (to the nearest ten bacteria) will be present in 10 hours
Answer:
If rounded to the nearest 10 bacteria, then it would be 500 bacteria.
Step-by-step explanation:
First multiply 150 by two in order to get 300, that leaves 4 hours to figure out. From there you can figure out the rest by seeing that 4 is 2/3 of 6. I converted it into the decimal number .66. Multiply 300 by .66 to get 198 and then add it to 300 to get 498. Then just round it up to the nearest 10 bacteria which leaves you with the final answer of 500 bacteria.
Select the correct answer.
Which chart best represents the following information about student results from a class assignment?
Answer
a) chart
Step-by-step explanation:
a) chart best represents the following information about student results from a class assignment
It is believed that students who begin studying for final exams a week before the test score differently than students who wait until the night before. Suppose you want to test the hypothesis that students who study one week before score less than students who study the night before. A hypothesis test for two independent samples is run based on your data and a p-value is calculated to be 0.2789. What is the appropriate conclusion
Answer:
The p-value is 0.2789 > 0.05, which means that the appropriate conclusion is that the students do not score differently.
Step-by-step explanation:
It is believed that students who begin studying for final exams a week before the test score differently than students who wait until the night before.
At the null hypothesis, we test if the two means are equal, that is, the subtraction of them is 0.
[tex]H_0: \mu_1 - \mu_2 = 0[/tex]
At the alternative hypothesis, we test if the two means are different, that is, the subtraction of them is different of 0. So
[tex]H_1: \mu_1 - \mu_2 \neq 0[/tex]
A hypothesis test for two independent samples is run based on your data and a p-value is calculated to be 0.2789.
Considering a standard significance level of 0.02789, the p-value is 0.2789 > 0.05, which means that the appropriate conclusion is that the students do not score differently.
The head of maintenance at XYZ Rent-A-Car believes that the mean number of miles between services is 4959 miles, with a standard deviation of 448 miles. If he is correct, what is the probability that the mean of a sample of 43 cars would differ from the population mean by less than 111 miles
Answer:
0.8948 = 89.48% probability that the mean of a sample of 43 cars would differ from the population mean by less than 111 miles
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
The mean number of miles between services is 4959 miles, with a standard deviation of 448 miles
This means that [tex]\mu = 4959, \sigma = 448[/tex]
Sample of 43:
This means that [tex]n = 43, s = \frac{448}{\sqrt{43}}[/tex]
What is the probability that the mean of a sample of 43 cars would differ from the population mean by less than 111 miles?
p-value of Z when X = 4959 + 111 = 5070 subtracted by the p-value of Z when X = 4959 - 111 = 4848, that is, probability the sample mean is between these two values.
X = 5070
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{5070 - 4959}{\frac{448}{\sqrt{43}}}[/tex]
[tex]Z = 1.62[/tex]
[tex]Z = 1.62[/tex] has a p-value of 0.9474
X = 4848
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{4848 - 4959}{\frac{448}{\sqrt{43}}}[/tex]
[tex]Z = -1.62[/tex]
[tex]Z = -1.62[/tex] has a p-value of 0.0526
0.9474 - 0.0526 = 0.8948
0.8948 = 89.48% probability that the mean of a sample of 43 cars would differ from the population mean by less than 111 miles
8-6•4+10divided by 2 =
Subtract 8 1/5 - 4 2/5 . Simplify the answer and write as a mixed number.
Answer:
[tex]3\frac{4}{5}[/tex]
Step-by-step explanation:
Hi there!
»»————- ★ ————-««
I believe your answer is:
[tex]3\frac{4}{5}[/tex]
»»————- ★ ————-««
Here’s why:
⸻⸻⸻⸻
[tex]\boxed{\text{Calculating the answer...}}\\\\8\frac{1}{5}-4 \frac{2}{5}\\-------------\\\text{Converting the mixed numbers into improper fractions...}\\\\\rightarrow 8\frac{1}{5} =\frac{41}{5}\\\\\rightarrow 4\frac{2}{5}=\frac{22}{5} \\-------------\\\frac{41}{5} -\frac{22}{5}\\\\\rightarrow\boxed{ \frac{19}{5}}\\-------------\\\\text{5 would go into 19 3 times with 4 as the remainder.}\\\\\frac{19}{5}=\boxed{3\frac{4}{5}}\\-------------\\\text{\textbf{Therefore:}}\\\\[/tex]
[tex]8\frac{1}{5}-4\frac{2}{5}=\boxed{3\frac{4}{5}}[/tex]
⸻⸻⸻⸻
»»————- ★ ————-««
Hope this helps you. I apologize if it’s incorrect.
PLZZZZ HELPP WILL GIVE BRAINLIEST
Two sides and the non-included right angle of one right triangle are congruent to the corresponding parts of another right triangle. Which congruence theorem can be used to prove that the triangles are congruent?
AAS
SSS
SAS
HL
Answer:
HL
Step-by-step explanation:
Since both triangles are right angle triangles that means one angle is 90°. other two sides are given congruent .
that means lengths of hypotenuse and the leg of the one right angle triangle is equal to the corresponding other hypotenuse and leg of other triangle.
This fulfills the condition of HL congruency.
Find the area of the figure below, formed from a triangle and a parallelogram.
144 square millimeters
120 square millimeters
72 square millimeters
96 square millimeters
total area =A1+A2+A3
A1=1/2b*h
A1=1/2*8mm*6mm
A1=24mmsquare
A2=1/2b*h
A2=1/2*8mm*6mm
A2=24mmsquare
A3=b*h
A3=8mm*6mm
A3=48mmsquare
Atotal=24mmsquare+24mmsquare+48mmsquare
Atotal=96mmsquare
Using the quadratic formula, which of the following are the zeros of the quadratic equation below? y=x^2-x-5
Answer:
The roots(Zeros) are
x=2.7913 and -1.7913
What is the slope of the line?
(2cosA+1) (2cosA-1)=2cos2A+1 prove that
To prove that: (2cosA+1) (2cosA-1) = 2cos2A+1
We try to solve one side of the equation to get the other side of the equation.
In this case, we'll solve the right hand side (2cos2A + 1) of the equation with the aim of getting the left hand side of the equation (2cosA + 1)(2cosA - 1)
Solving the right hand side: 2cos2A + 1
i. We know that cos2A = cos(A+A) = cosAcosA - sinAsinA
Therefore;
cos2A = cos²A - sin²A
ii. We also know that: cos²A + sin²A = 1
Therefore;
sin²A = 1 - cos²A
iii. Now re-write the right hand side by substituting the value of cos2A as follows;
2cos2A + 1 = 2(cos²A - sin²A) + 1
iv. Expand the result in (iii)
2cos2A + 1 = 2cos²A - 2sin²A + 1
v. Now substitute the value of sin²A in (ii) into the result in (iv)
2cos2A + 1 = 2cos²A - 2(1 - cos²A) + 1
vi. Solve the result in (v)
2cos2A + 1 = 2cos²A - 2 + 2cos²A + 1
2cos2A + 1 = 4cos²A - 2 + 1
2cos2A + 1 = 4cos²A - 1
2cos2A + 1 = (2cosA)² - 1²
vii. Remember that the difference of the square of two numbers is the product of the sum and difference of the two numbers. i.e
a² - b² = (a+b)(a-b)
This means that if we put a = 2cosA and b = 1, the result from (vi) can be re-written as;
2cos2A + 1 = (2cosA)² - 1²
2cos2A + 1 = (2cosA + 1)(2cosA - 1)
Since, we have been able to arrive at the left hand side of the given equation, then we can conclude that;
(2cosA + 1)(2cosA - 1) = 2cos2A + 1
Answer:
[tex]\boxed{\sf LHS = RHS }[/tex]
Step-by-step explanation:
We need to prove that ,
[tex]\sf\implies (2 cosA +1)(2cosA-1) = 2cos2A+1[/tex]
We can start by taking RHS and will try to obtain the LHS . The RHS is ,
[tex]\sf\implies RHS= 2cos2A + 1 [/tex]
We know that , cos2A = 2cos²A - 1 ,
[tex]\sf\implies RHS= 2(2cos^2-1)-1 [/tex]
Simplify the bracket ,
[tex]\sf\implies RHS= 4cos^2A - 2 +1 [/tex]
Add the constants ,
[tex]\sf\implies RHS= 4cos^2-1 [/tex]
Write each term in form of square of a number ,
[tex]\sf\implies RHS= (2cos^2A)^2-1^2 [/tex]
Using (a+b)(a-b) = a² - b² , we have ,
[tex]\sf\implies RHS= (2cosA+1)(2cosA-1) [/tex]
This equals to LHS , therefore ,
[tex]\sf\implies \boxed{\pink{\textsf{\textbf{ RHS= LHS }}}} [/tex]
Hence Proved !
if x+y=12 and xy =27,then find the value of x^2+y^2
PLEASE HELP !
Answer:
90
Step-by-step explanation:
=> x + y = 12
=> x² + y² + 2xy = 144
=> x² + y² + 2 * 27 = 144
=> x² + y² = 144 - 54
=> x² + y² = 90
You return from a trip with 480 Canadian dollars. How much are your Canadian dollars worth in U.S. dollars? Use the exchange rate shown below. Currency U.S. dollars per Canadian dollar Canadian dollars per U.S. dollar Canadian dollar 0.5823 1.717 The 480 Canadian dollars are equivalent to about $ (Round to the nearest cent as needed.)
591 Dollars 42 Cents (591 Dollars when rounded)
Pyramid Lake is on the Paiute Indian Reservation in Nevada. The lake is famous for cutthroat trout. Suppose a friend tells you that the average length of trout caught in Pyramid Lake is µ = 19 inches. However, a survey reported that of a random sample of 46 fish caught, the mean length was x = 18.6 inches, with estimated standard deviation s = 3.1 inches. Do these data indicate that the average length of a trout caught in Pyramid Lake is less than µ = 19 inches? Use ???? = 0.05.
Answer:
The test statistics will be "-0.876",
Step-by-step explanation:
Given:
[tex]\bar x=18.6[/tex][tex]\mu = 19[/tex][tex]s = 3.1[/tex][tex]n = 46[/tex]According to the question,
Level of significance will be:
= 0.05
Now,
The test statistics will be:
= [tex]\frac{\bar x-\mu}{\frac{s}{\sqrt{n} } }[/tex]
By substituting the values, we get
= [tex]\frac{18.6-19}{\frac{3.1}{\sqrt{46} } }[/tex]
= [tex]-\frac{2.713}{3.1}[/tex]
= [tex]-0.876[/tex]
Quality control. As part of a quality control process for computer chips, an engineer at a factory randomly samples 212 chips during a week of production to test the current rate of chips with severe defects. She finds that 27 of the chips are defective.
(a) What population is under consideration in the data set?
(b) What parameter is being estimated?
(c) What is the point estimate for the parameter?
(d) What is the name of the statistic can we use to measure the uncertainty of the point estimate?
(e) Compute the value from part (d) for this context.
(f) The historical rate of defects is 10%. Should the engineer be surprised by the observed rate of defects
during the current week?
(g) Suppose the true population value was found to be 10%. If we use this proportion to recompute the value in part (e) using p = 0.1 instead of pˆ, does the resulting value change much?
Answer:
See Explanation
Step-by-step explanation:
According to the Question,
Given That, As part of a quality control process for computer chips, an engineer at a factory randomly samples 212 chips during a week of production to test the current rate of chips with severe defects. She finds that 27 of the chips are defective.(a) The sample is from all computer chips manufactured at the factory during the week of production. We might be tempted to generalize the population to represent all weeks, but we should exercise caution here since the rate of defects may change over time.
(b) The fraction of computer chips manufactured at the factory during the week of production that had defects.
(c) Estimate the parameter using the data: phat = 27/212 = 0.127.
(d) Standard error (or SE).
(e) Compute the SE using phat = 0.127 in place of p:
SE ≈ √(phat(1−phat)/n) = 0.023.
(f) The standard error is the standard deviation of phat. A value of 0.10 would be about one standard error away from the observed value, which would not represent a very uncommon deviation. (Usually beyond about 2 standard errors is a good rule of thumb.) The engineer should not be surprised.
(g) Recomputed standard error using p = 0.1: SE = 0.021. This value isn't very different, which is typical when the standard error is computed using relatively similar proportions (and even sometimes when those proportions are quite different!).
ANSWER ASAPPPP I WILL GIVE BRAINLIEST AND DROP POINTS AFTER
The function f(t) = t2 + 4t − 14 represents a parabola.
Part A: Rewrite the function in vertex form by completing the square. Show your work. (6 points)
Part B: Determine the vertex and indicate whether it is a maximum or a minimum on the graph. How do you know? (2 points)
Part C: Determine the axis of symmetry for f(t). (2 points)
(10 points)
Answer:
A: f(t) = t2(4t) - 14
B: It is a maximum because it continues redistributing forever.
C: Assuming you plotted this on a 0/0 grid, your axis of symetry would be at 18/28
Hope this helps, please mark brainliest
Step-by-step explanation:
A: it is simple really, your just redistributing each T to itself, which is what makes a square / vertex.
ANSWER QUICKLY!!! What is the median of Restaurant B's cleanliness ratings?
4
3
1
5
2
Your money grows at a rate of 8% a year if you originally invest $2,000 what is the function that represents your money after t years
Answer:
2000*(1.08)^t where t is years after deposit
Step-by-step explanation:
Formular for quadratic equation almighty formular
[tex]x = \frac{ - b \frac{ + }{} \sqrt{ {b}^{2} - 4ac } }{2a} [/tex]
You want to send postcards to 15 friends. In the shop there are only 3 kinds of postcards. In how many ways can you send the postcards, if
Answer:
455 ways
Step-by-step explanation:
Given
[tex]n = 15[/tex] --- friends
[tex]r = 3[/tex] -- available postcard kinds
Required
Ways of sending the cards
The question is an illustration of combination and the formula is:
[tex]^nC_r = \frac{n!}{(n - r)!r!}[/tex]
So, we have:
[tex]^{15}C_3 = \frac{15!}{(15 - 3)!3!}[/tex]
[tex]^{15}C_3 = \frac{15!}{12!*3!}[/tex]
Expand
[tex]^{15}C_3 = \frac{15*14*13*12!}{12!*3*2*1}[/tex]
[tex]^{15}C_3 = \frac{15*14*13}{3*2*1}[/tex]
[tex]^{15}C_3 = \frac{2730}{6}[/tex]
[tex]^{15}C_3 = 455[/tex]
Please answer of question num 20 and 21 only please
Answer:
Iam going to do question 21
Step-by-step explanation:
1/7*x=2
1/7x=2
x=2:1/7
x=2*7/1
x=14
How many x-intercepts are in the quadratic equation y = 7x2 − 2x − 1
Answer:
There are 2 x intercepts
X is a normally distributed random variable with a mean of 22 and a standard deviation of 5. The probability that x is less than 9.7 is:_________
a. 0.0069
b. 0.000
c. 0.4931
d. 0.9931
Answer:
0.0069
Step-by-step explanation:
According to the Question,
Given That, X is a normally distributed random variable with a mean of 22 and a standard deviation of 5. The probability that x is less than 9.7We have, μ=22 , σ= 5 , P(X<9.7)=Area to the left of 9.7.
Z = (x-μ)/σ
Z = (9.7-22) / 5 ⇒ -2.46
Thus,
P(X<9.7)=P(Z < -2.46) ⇒ 0.0069 (From z-table)Help ! ASAP please and thank you !!
that alot of work shhheeshhh
Can someone do eight nine one and two ?
Answer: hello there here are your answers:
8) B multiplication property of zero
9) C additive identify
1) 8
2) -2a-7
Step-by-step explanation:
1) [tex]\frac{3+u}8^{2} \\u=5 \\so\\ \frac{3+5}8^{2} \\3+5=8^{2} \\8^{2} =\\64 \\\\ 64/8=\\\\\\8 \\there.\\\\\\[/tex]
2)[tex]-2(a-7)\\\\-2(a)(-7)\\\\=-2a+14\\\\\\there[/tex]