Question

Find all solutions to the equation $x^2 - 8x = -16$.

Answer 1

x = 4

Explanation:

x^2 - 8x = -16

Add 16 to both sides.

x^2 8x + 16 = 0

This may be the square of a binomial.

x^2 is the square of x

16 is the square of 4 and -4.

Let's check the middle term:

2ab = 2(x)(-4) = -8x

Yes, it is the square of a binomial.

x^2 - 8x + 16 = 0

(x - 4)^2 = 0

x - 4 = 0 or x - 4 = 0

x = 4 or x = 4

Answer: x = 4