42=9y-3y

Solution for 42=9y-3y equation:

Simplifying
42 = 9y + -3y

Combine like terms: 9y + -3y = 6y
42 = 6y

Solving
42 = 6y

Solving for variable 'y'.

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

Add '-6y' to each side of the equation.
42 + -6y = 6y + -6y

Combine like terms: 6y + -6y = 0
42 + -6y = 0

Add '-42' to each side of the equation.
42 + -42 + -6y = 0 + -42

Combine like terms: 42 + -42 = 0
0 + -6y = 0 + -42
-6y = 0 + -42

Combine like terms: 0 + -42 = -42
-6y = -42

Divide each side by '-6'.
y = 7

Simplifying
y = 7