x(x-4)+4(x+4)=800

Solution for x(x-4)+4(x+4)=800 equation:

Simplifying
x(x + -4) + 4(x + 4) = 800

Reorder the terms:
x(-4 + x) + 4(x + 4) = 800
(-4 * x + x * x) + 4(x + 4) = 800
(-4x + x2) + 4(x + 4) = 800

Reorder the terms:
-4x + x2 + 4(4 + x) = 800
-4x + x2 + (4 * 4 + x * 4) = 800
-4x + x2 + (16 + 4x) = 800

Reorder the terms:
16 + -4x + 4x + x2 = 800

Combine like terms: -4x + 4x = 0
16 + 0 + x2 = 800
16 + x2 = 800

Solving
16 + x2 = 800

Solving for variable 'x'.

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

Add '-16' to each side of the equation.
16 + -16 + x2 = 800 + -16

Combine like terms: 16 + -16 = 0
0 + x2 = 800 + -16
x2 = 800 + -16

Combine like terms: 800 + -16 = 784
x2 = 784

Simplifying
x2 = 784

Take the square root of each side:
x = {-28, 28}