Solve the system by substitution.
x + y=12, y = 2x
Solve x + 2x = 12
That is the same as 3x = 12
Divide both sides by 3 for the value of x. Then use either equaiton to get y.
x + y=12, y = 2x
That is the same as 3x = 12
Divide both sides by 3 for the value of x. Then use either equaiton to get y.