<span>Simplifying
3x + -1y = 12
Solving
3x + -1y = 12
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add 'y' to each side of the equation.
3x + -1y + y = 12 + y
Combine like terms: -1y + y = 0
3x + 0 = 12 + y
3x = 12 + y
Divide each side by '3'.
x = 4 + 0.3333333333y
Simplifying
x = 4 + 0.3333333333y</span>
