42=y-20

Solution for 42=y-20 equation:

Simplifying
42 = y + -20

Reorder the terms:
42 = -20 + y

Solving
42 = -20 + 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.
42 + -1y = -20 + y + -1y

Combine like terms: y + -1y = 0
42 + -1y = -20 + 0
42 + -1y = -20

Add '-42' to each side of the equation.
42 + -42 + -1y = -20 + -42

Combine like terms: 42 + -42 = 0
0 + -1y = -20 + -42
-1y = -20 + -42

Combine like terms: -20 + -42 = -62
-1y = -62

Divide each side by '-1'.
y = 62

Simplifying
y = 62