Question

Which function is equivalent to (x)=-7(x+4)2-1?

a : f(x)=-7x2 + 8x+15

b : F(x)=-7x2-56x-113

C : f(x)=-7x2-56x-105

d : f(x)=-7x2 + 111

Answer 1

answer : b

Explanation:

hello :

calculate : f (x)=-7(x+4)²-1

f(x) = -7(x²+16+8x) -1 use identity : (a+b)² = a²+b²+2ab

f(x) = -7x²-112 -56x -1

f(x) = -7x²-56x -113