Simplifying
99 + 5x = 2000 + -5x + -911

Reorder the terms:
99 + 5x = 2000 + -911 + -5x

Combine like terms: 2000 + -911 = 1089
99 + 5x = 1089 + -5x

Solving
99 + 5x = 1089 + -5x

Solving for variable 'x'.

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

Add '5x' to each side of the equation.
99 + 5x + 5x = 1089 + -5x + 5x

Combine like terms: 5x + 5x = 10x
99 + 10x = 1089 + -5x + 5x

Combine like terms: -5x + 5x = 0
99 + 10x = 1089 + 0
99 + 10x = 1089

Add '-99' to each side of the equation.
99 + -99 + 10x = 1089 + -99

Combine like terms: 99 + -99 = 0
0 + 10x = 1089 + -99
10x = 1089 + -99

Combine like terms: 1089 + -99 = 990
10x = 990

Divide each side by '10'.
x = 99

Simplifying
x = 99