Simplifying
x + 1 = 9

Reorder the terms:
1 + x = 9

Solving
1 + x = 9

Solving for variable 'x'.

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

Add '-1' to each side of the equation.
1 + -1 + x = 9 + -1

Combine like terms: 1 + -1 = 0
0 + x = 9 + -1
x = 9 + -1

Combine like terms: 9 + -1 = 8
x = 8

Simplifying
x = 8