Substitution Method (again)

Today we went over substitution method again, because it seemed that no body showed their work, or did the homework at all. Mr. Maksymchuk showed us how to turn 1 line into the variable we would be substituting into the other line ( e.g X) in order to find one variable (Y) which we could then substitute inorder to find the X variable. Or something like that...

Enjoy;