63+-21=y

Solution for 63+-21=y equation:

Simplifying
63 + -21 = y

Combine like terms: 63 + -21 = 42
42 = y

Solving
42 = 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 = y + -1y

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

Add '-42' to each side of the equation.
42 + -42 + -1y = 0 + -42

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

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

Divide each side by '-1'.
y = 42

Simplifying
y = 42