x is a real number?

Question

Solve (x + 4)^2 - 20 = 0 where x is a real number.
Simplify your answer as much as possible

If there is more than one solution than write them all

Answer 1

By looking at it, this is a quadratic equation and x MUST have two values.

First, expand the equation [(x + 4)^2 = (a^2 +2ab + b^2)]
x^2 + 8x + 16 - 20 = 0

Then, solve it
x^2 + 8x - 4 = 0

By using a calculator,
x = 0.4495, -4.45 (final answer)

Answer 2

Expanding and combining terms, we have x^2 + 8x -4 = 0, so x = (-8 +/- sqrt(80))/2, or x = -4 +/- 2 sqrt(5).

Answer 3

x={-8.472136,.47213595}