Answer:
C
Step-by-step explanation:
Mean is just another name for average. To find the mean of a data set, add all the values together and divide by the number of values in the set. The result is your mean!
Answer:
9
Step-by-step explanation:
The answer is <span>b.12
</span>
According to the Pythagorean theorem the square of the hypotenuse (c) is the sum of the squares of the legs (a and b):
c² = a² + b²
We have:
a = 3x
b = 15
c = 3x + 3
Now, let's replace these parameters:
c² = a² + b²
(3x + 3)² = (3x)² + 15²
(3x)² + 2 * 3x * 3 + 3² = 9x² + 225
9x² + 18x + 9 = 9x² + 225
Rearrange:
9x² - 9x² + 18x = 225 - 9
18x = 216
x = 216 / 18 = 12
Answer: r - 24
Step-by-step explanation:


![\frac{[(r+2)(2r-9)]-(r^2+17r+30)}{r+2}](https://tex.z-dn.net/?f=%5Cfrac%7B%5B%28r%2B2%29%282r-9%29%5D-%28r%5E2%2B17r%2B30%29%7D%7Br%2B2%7D)



Combine like terms;

Solve the quadratic equation;

Simplify;

-(-7y + 12) = 7y - 12
u are distributing the -sign through the parenthesis...so u take the number outside of the parenthesis (and if it just a sign, the number is 1)...and u multiply it by everything in the parenthesis.
-1(-7y + 12) = -1 * -7y + (-1) * 12 = 7y + (-12) = 7y - 12