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2 years ago

Factor each trinomial completely. 4x^2 - 25b^2 and x^2 - 81

Mathematics

1 answer:

GenaCL600 [577]2 years ago

8 0

Step-by-step explanation:

4x2 - 25b2

We can solve it by the squares so

(2x - 5b) (2x + 5b)

2) x2 - 81

The same case is here so

(x - 9) (x + 9)

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Suppose that at a state college, a random sample of 41 students is drawn, and each of the 41 students in the sample is asked to

ra1l [238]

Answer:

The confidence interval for 90% confidence would be narrower than the 95% confidence

Step-by-step explanation:

From the question we are told that

The sample size is n = 41

For a 95% confidence the level of significance is $\alpha = [100 - 95]\% = 0.05$ and

the critical value of $\frac{\alpha }{2}$ is $Z_{\frac{\alpha }{2} } =Z_{\frac{0.05 }{2} }= 1.96$

For a 90% confidence the level of significance is $\alpha = [100 - 90]\% = 0.10$ and

the critical value of $\frac{\alpha }{2}$ is $Z_{\frac{\alpha }{2} } =Z_{\frac{0.10 }{2} }= 1.645$

So we see with decreasing confidence level the critical value decrease

Now the margin of error is mathematically represented as

$E = Z_{\frac{\alpha }{2} } * \frac{s}{\sqrt{n} }$

given that other values are constant and only $Z_{\frac{\alpha }{2} }$ is varying we have that

$E\ \ \alpha \ \ Z_{\frac{\alpha }{2} }$

Hence for reducing confidence level the margin of error will be reducing

The confidence interval is mathematically represented as

$\= x - E < \mu < \= x + E$

Now looking at the above formula and information that we have deduced so far we can infer that as the confidence level reduces , the critical value reduces, the margin of error reduces and the confidence interval becomes narrower

3 0

2 years ago

You buy 6 apples for $33. WHat is the cost of 10 pounds of apples

Mariana [72]

10 lbs of apples will cost $55

How? Well...

First, you would need to find the unit rate, which is 5.5
You find the unit rate by simply dividing 33 by 6. Next, after you found your unit rate, you're going to multiply that by 10. We now know that 10 x 5.5= 55. Therefore, you will need $55 for 10 lbs of apples.

5 0

2 years ago

What is the rate of change between (29,9) and (33,10)?

kramer

Answer:

m= 1/4

Step-by-step explanation:

tried helping I don't know if this is the right way to do it for you

6 0

2 years ago

2.38+4.89=3+ _ <br><br>changing expressions??

Lerok [7]

Add 2.38 and 4.89 then subtract 3 giving you 4.27

3 0

3 years ago

Which can be used to expand the expression below?

KiRa [710]

Answer:

Distributive Property

Step-by-step explanation:

We have

5(3x - 6/7)

Distributive Property would work because 5 has to be mutliplied by 3x and -6/7 to rid the parenthesis and also give a final answer for the equation. Any others will lead to a wrong answer.

7 0

2 years ago

Read 2 more answers