Question

Solve the quadratic equation. (x + 1)^2 = 16

A) x = 3 or -5 B) x = -3 or 5 C) x = ±5 D) x = ±1

Answer 1

If the square of a certain quantity must be 16, that quantity must be either 4 or -4.

In fact, in both cases we have
`4^2=(-4)^2=16`

So, we have two possible solutions:

`x+1=4 \iff x=3`

`x+1=-4 \iff x=-5`

Answer 2

A. x= 3 or -5

Explanation:

The solution is x = 3 or -5. The steps for solving the equation are shown.

(x + 1)2 = 16

(x + 1)2

= ±

16

x + 1 = ± 4

x + 1 = 4 or x + 1 = -4

x = 3 or -5