Is the relation a function?<br> {(4, 10), (7,6), (3,8), (11, 10), (7,15)}

How do you solve this? r^2+32=12r

Andre45 [30]

Answer:

r = {-8, -4}

Step-by-step explanation:

Simplifying

r2 = -32 + -12r

Solving

r2 = -32 + -12r

Solving for variable 'r'.

Reorder the terms:

32 + 12r + r2 = -32 + -12r + 32 + 12r

Reorder the terms:

32 + 12r + r2 = -32 + 32 + -12r + 12r

Combine like terms: -32 + 32 = 0

32 + 12r + r2 = 0 + -12r + 12r

32 + 12r + r2 = -12r + 12r

Combine like terms: -12r + 12r = 0

32 + 12r + r2 = 0

Factor a trinomial.

(8 + r)(4 + r) = 0

Subproblem 1

Set the factor '(8 + r)' equal to zero and attempt to solve:

Simplifying

8 + r = 0

Solving

8 + r = 0

Move all terms containing r to the left, all other terms to the right.

Add '-8' to each side of the equation.

8 + -8 + r = 0 + -8

Combine like terms: 8 + -8 = 0

0 + r = 0 + -8

r = 0 + -8

Combine like terms: 0 + -8 = -8

r = -8

Simplifying

r = -8

Subproblem 2

Set the factor '(4 + r)' equal to zero and attempt to solve:

Simplifying

4 + r = 0

Solving

4 + r = 0

Move all terms containing r to the left, all other terms to the right.

Add '-4' to each side of the equation.

4 + -4 + r = 0 + -4

Combine like terms: 4 + -4 = 0

0 + r = 0 + -4

r = 0 + -4

Combine like terms: 0 + -4 = -4

r = -4

Simplifying

r = -4

Solution

r = {-8, -4}

3 0

2 years ago

An automobile manufacturer would like to know what proportion of its customers are not satisfied with the service provided by th

monitta

Answer:

a) n =1623

b) $ME=2.0538\sqrt{\frac{0.21 (1-0.21)}{1623}}=0.0208$

Step-by-step explanation:

1) Notation and definitions

$n$ random sample taken

$\hat p=0.19$ estimated proportion of customers are not satisfied with the service provided by the local dealer

Confidence =0.96 or 96%

Me= 0.02 represent the margin of error

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Part a

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 96% of confidence, our significance level would be given by $\alpha=1-0.96=0.04$ and $\alpha/2 =0.02$ . And the critical value would be given by:

$z_{\alpha/2}=-2.0538, z_{1-\alpha/2}=2.0538$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.02$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.19(1-0.19)}{(\frac{0.02}{2.0538})^2}=1622.912$

And rounded up we have that n=1623

Part b

The margin of error is given by:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

So then if w replace the value of n obtained from part a we got:

$ME=2.0538\sqrt{\frac{0.21 (1-0.21)}{1623}}=0.0208$

3 0

2 years ago

PLEASE HELP ASAP HURRY

bulgar [2K]

Answer: The amount she pays for admission

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Round 27346 to 2 significant figures i need a step by step expansion

belka [17]

Answer:

27000

Step-by-step explanation:

We want to round 27346 to 2 significant figures.

Now, the number already has 5 significant figures, so to reduce it to 2 sig figures, we will have to reduce the 3 digits from the right to zero so that we can have just 2 significant figures by approximating.

Thus, 3 is less than 5 and so 7 cannot increase. Thus, we will have 27000 as the number when reduced to 2 significant figures.

5 0

3 years ago

In a certain clothing store,6 shirts and 3 ties cost $79.50 ,and 3 shirts and 2 ties cost $41. determine the cost of each shirt.

Komok [63]

Answer:

Each shirt cost $12

Step-by-step explanation:

First, we have to interpret this question and turn each to an equation, letting shirts represent the letter s and ties represent the letter t.

6 shirts and 3 ties cost $79.50 would be interpreted to 6s+3t=79.5 ,and 3 shirts and 2 ties cost $41 would be interpreted to 3s+2t=41

Hence we have two equations, and we solve them simultaneously.

6s+3t=79.5 (Equation 1)

3s+2t=41 (Equation 2)

We can either use the substitution method or the elimination method but for the sake of this question, we use the Elimination method.

6s+3t=79.5 (Equation 1)

3s+2t=41 (Equation 2)

We multiply equation 1 by 2 and we multiply equation 2 by 3, I'm prefer to eliminate the

2(6s+3t=79.5)

12s+6t=159 Equation 3

3(3s+2t=41)

9s+6t=123 Equation 4

We subtract equation 4 from equation 3.

12s+6t=159

9s+6t=123

12s-9s=3s

6t-6t=0

159-123=36

We therefore have

3s=36

Divide both sides by 3

s=36/3

s=12

One shirt cost $12

3 0

3 years ago

Is the relation a function? {(4, 10), (7,6), (3,8), (11, 10), (7,15)}