x(x+2)=77+2(x+2)

Solution for x(x+2)=77+2(x+2) equation:

Simplifying
x(x + 2) = 77 + 2(x + 2)

Reorder the terms:
x(2 + x) = 77 + 2(x + 2)
(2 * x + x * x) = 77 + 2(x + 2)
(2x + x2) = 77 + 2(x + 2)

Reorder the terms:
2x + x2 = 77 + 2(2 + x)
2x + x2 = 77 + (2 * 2 + x * 2)
2x + x2 = 77 + (4 + 2x)

Combine like terms: 77 + 4 = 81
2x + x2 = 81 + 2x

Add '-2x' to each side of the equation.
2x + -2x + x2 = 81 + 2x + -2x

Combine like terms: 2x + -2x = 0
0 + x2 = 81 + 2x + -2x
x2 = 81 + 2x + -2x

Combine like terms: 2x + -2x = 0
x2 = 81 + 0
x2 = 81

Solving
x2 = 81

Solving for variable 'x'.

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

Simplifying
x2 = 81

Take the square root of each side:
x = {-9, 9}