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3 years ago

If (8z − 9)(8z + 9) = az2 − b, what is the value of a? (5 points)

1 answer:

3 0

The question is looking for the coefficient to the first term after multiplying the two sets of parentheses together.

=(8z − 9)(8z + 9)
using the FOIL method, multiply the first, outside, inside, then last terms

=(8z*8z) + (8z*9) + (-9*8z) + (-9*9)
=64z^2 + 72z - 72z - 81
the middle two terms cancel each other (72-72= 0)
=64z^2 - 81

ANSWER: The value of a is 64

Hope this helps! :)

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which polynomial correctly combines the like terms and expresses the given polynomial in standard form? 8mn5-2m6+5m2n4-m3n3+n6-4

Lelechka [254]

Answer:

The answer would be 7mn^5 - 2m^6 + 14m^2n^4 - 5m^3n^3 + n^6

Step-by-step explanation:

In order to find that answer, start by grouping all of the terms by their variable values. Ones that are the same should be combined.

8mn^5 - mn^5 = 7mn^5

2m^6 - 4m^6 = -2m^6

5m^2n^4 + 9m^2n^4 = 14m^2n^4

-m^3n^3 - 4m^3n^3 = -5m^3n^3

n^6 = n^6

Now we simply combine them all to get

7mn^5 - 2m^6 + 14m^2n^4 - 5m^3n^3 + n^6

6 0

4 years ago

Please answer ASAP....................................................thanks

Nikolay [14]

Answer:

I'm going to say answer B for the first question. I'm not sure for the second question.

Step-by-step explanation:

Angles are congruent when they are the same size.

5 0

3 years ago

What is the equation of the best-fitting regression line? Find this in two ways. First, using the regression analysis part of th

Lemur [1.5K]

Step-by-step explanation:

Regression analysis is used to infer about the relationship between two or more variables.

The line of best fit is a straight line representing the regression equation on a scatter plot. The may pass through either some point or all points or none of the points.

Method 1:

Using regression analysis the line of best fit is: $y=\alpha +\beta x+e$

Here α = intercept, β = slope and e = error.

The formula to compute the intercept is:

$\alpha =\bar y-\beta \bar x$

Here $\bar y$ and $\bar x$ are mean of the y and x values respectively.

$\bar y=\frac{\sum y_{i}}{n} \\\bar x=\frac{\sum x_{i}}{n}$

The formula to compute the slope is:

$\beta =\frac{\sum (x-\bar x)(y - \bar y)}{\sum (x=\bar x)^{2}}$

And the formula to compute the error is:

$e=y-\alpha -\beta x$

Method 2:

The regression line can be determined using the descriptive statistics mean, standard deviation and correlation.

The equation of the line of best fit is:

$(y-\bar y)=r\frac{\sigma_{x}}{\sigma_{y}} (x-\bar x)$

Here r = correlation coefficient = $r=\frac{Cov (x,y)}{\sqrt{\sigma^{2}_{x}\sigma^{2}_{y}} }$

$\sigma_{x}$ and $\sigma_{y}$ are standard deviation of x and y respectively.

$\sigma_{x}=\frac{1}{n}\sum (x-\bar x)^{2} \\\sigma_{y}=\frac{1}{n}\sum (y-\bar y)^{2}$

3 0

3 years ago

Please its really urgent, step by step working out

Karo-lina-s [1.5K]

Answer:

70.99

Step-by-step explanation:

Use Pythagorean Theorem to find the shortest distance.

80^2-50^2=3900

Square rt= 62.44

Subtract by 15

47.44

Next find half of the circular path it is (3.14 x 15)/2

23.55

Add 47.44+23.55=70.99

Hope this is correct

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3 years ago

How many strings are there of four lowercase letters that have the letter x in them?

borishaifa [10]

We can subtract from the number of strings of length 4 of lower case letters the number of string of length 4 of lower case letters other than x. Thus the answer is 264 − 254 = 66,351

6 0

4 years ago