,
Subtract from both sides of the equation.
Replace all occurrences of in with .
Simplify .
Simplify each term.
Apply the distributive property.
Multiply by .
Multiply by .
Combine the opposite terms in .
Add and .
Add and .
Remove any equations from the system that are always true.
Solve by Substitution x+3y=2 , 3x+9y=6