Question

What are the solutions to the quadratic equation 4(x + 2)2 = 36

A. x = −11 and x = 7
B. x = −7 and x = 11
C. x= −5 and x = 1
D. x = −1 and x = 5

Answer 1

4(-11 + 2)2 = -72
4(7 + 2)2 = 72
4(-7 + 2)2 = -40
4(11 + 2)2 = 104
4(-5 + 2)2 = -24
4(1 + 2)2 = 24
4(-1 + 2)2 = 8
4(5 + 2)2 = 56

Answer 2

C

Explanation:

Given

4(x + 2)² = 36 ( divide both sides by 4 )

(x + 2)² = 9 ( take the square root of both sides )

x + 2 = ±
`√(9)` = ± 3 ( subtract 2 from both sides )

x = - 2 ± 3 , then

x = - 2 - 3 = - 5 and x = - 2 + 3 = 1