90=15+x-15

Solution for 90=15+x-15 equation:

Simplifying
90 = 15 + x + -15

Reorder the terms:
90 = 15 + -15 + x

Combine like terms: 15 + -15 = 0
90 = 0 + x
90 = x

Solving
90 = x

Solving for variable 'x'.

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

Add '-1x' to each side of the equation.
90 + -1x = x + -1x

Combine like terms: x + -1x = 0
90 + -1x = 0

Add '-90' to each side of the equation.
90 + -90 + -1x = 0 + -90

Combine like terms: 90 + -90 = 0
0 + -1x = 0 + -90
-1x = 0 + -90

Combine like terms: 0 + -90 = -90
-1x = -90

Divide each side by '-1'.
x = 90

Simplifying
x = 90