Simplifying
3x + -10 + -1x = 90
Reorder the terms:
-10 + 3x + -1x = 90
Combine like terms: 3x + -1x = 2x
-10 + 2x = 90
Solving
-10 + 2x = 90
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '10' to each side of the equation.
-10 + 10 + 2x = 90 + 10
Combine like terms: -10 + 10 = 0
0 + 2x = 90 + 10
2x = 90 + 10
Combine like terms: 90 + 10 = 100
2x = 100
Divide each side by '2'.
x = 50
Simplifying
x = 50