(x+4)(2x-8)=0

Solution for (x+4)(2x-8)=0 equation:

Simplifying
(x + 4)(2x + -8) = 0

Reorder the terms:
(4 + x)(2x + -8) = 0

Reorder the terms:
(4 + x)(-8 + 2x) = 0

Multiply (4 + x) * (-8 + 2x)
(4(-8 + 2x) + x(-8 + 2x)) = 0
((-8 * 4 + 2x * 4) + x(-8 + 2x)) = 0
((-32 + 8x) + x(-8 + 2x)) = 0
(-32 + 8x + (-8 * x + 2x * x)) = 0
(-32 + 8x + (-8x + 2x2)) = 0

Combine like terms: 8x + -8x = 0
(-32 + 0 + 2x2) = 0
(-32 + 2x2) = 0

Solving
-32 + 2x2 = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '32' to each side of the equation.
-32 + 32 + 2x2 = 0 + 32

Combine like terms: -32 + 32 = 0
0 + 2x2 = 0 + 32
2x2 = 0 + 32

Combine like terms: 0 + 32 = 32
2x2 = 32

Divide each side by '2'.
x2 = 16

Simplifying
x2 = 16

Take the square root of each side:
x = {-4, 4}