Just add the two equations term by term. The coefficient on in one equation is the additive inverse of the coefficient on in the other equation. When you add them, the variable will be eliminated leaving you with a single equation in the single variable that can be solved by ordinary means. Once you have the value of , substitute it back into either of the original equations, and then solve for
Check your answer by substituting both values back into both original equations to ensure that you have a true statement in each case.