,

Eliminate the equal sides of each equation and combine.

Move all terms containing to the left side of the equation.

Add to both sides of the equation.

Add and .

Move all terms not containing to the right side of the equation.

Subtract from both sides of the equation.

Subtract from .

Divide each term by and simplify.

Divide each term in by .

Cancel the common factor of .

Cancel the common factor.

Divide by .

Divide by .

Substitute for .

Substitute for in and solve for .

Remove parentheses.

Simplify .

Multiply by .

Subtract from .

The solution of the system of equations is all the values that make the system true.

Solve by Substitution y=9+3z , y=51-3z