Answer:
D.) 8
Step-by-step explanation:
You can use the Pythagorean theorem because this is a right triangle:

a and b are the legs and c is the hypotenuse. The hypotenuse is always the longest side in a right triangle (since it is opposite the biggest angle). The two legs squared have to add up to the hypotenuse squared.
Fill in values:

Simplify exponents:

Isolate the variable. Subtract 225 from both sides:

Find the square root of both sides:

The missing leg length is 8.
Answer:
N = 3/8
Step-by-step explanation:
let the number be N
let's express the word sentence as a mathematical expression:
"a number multiplied by 2/5"
= "N" multiplied by 2/5
= N x (2/5)
= (2N/5) ------- (1)
"a number multiplied by 2/5 is 3/20" can be written as:
(2N/5) = 3/20 (multiplying both sides by 5)
2N = (3/20) x 5
2N = 3/4 (divide both sides by 2)
N = (3/4) ÷ 2
N = (3/4) x (1/2)
N = 3/8
Answers for A:
Factored form: (x-2)(x+4)
Zeros: x = 2, -4
Vertex: (-1, -9)
Answers for B:
Factored form: -(x+2)(x+7)
Zeros: x = -2, -7
Vertex: (-9/2, 25/4)
-2x-6
EXPLANATION
(3x-5) = (-2x) - 6