42-(-91)=y

Solution for 42-(-91)=y equation:

Simplifying
42 + -1(-91) = y

Multiply -1 * -91
42 + 91 = y

Combine like terms: 42 + 91 = 133
133 = y

Solving
133 = y

Solving for variable 'y'.

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

Add '-1y' to each side of the equation.
133 + -1y = y + -1y

Combine like terms: y + -1y = 0
133 + -1y = 0

Add '-133' to each side of the equation.
133 + -133 + -1y = 0 + -133

Combine like terms: 133 + -133 = 0
0 + -1y = 0 + -133
-1y = 0 + -133

Combine like terms: 0 + -133 = -133
-1y = -133

Divide each side by '-1'.
y = 133

Simplifying
y = 133