** Hour 18**

** Solving Systems of Equations: Combined Operations**

**T**he three choices for solving a system of equations give you the flexibility to decide which is most appropriate for each system. If graphing equations as lines helps you see the solution in a clearer way than the algebraic options do, use your graphing skills. As you look at the two equations in a given system, the most efficient option will often be obvious. The substitution and addition methods let you use your algebra skills to solve these rather complex problems, but you can decide which of the three might work best in a given system.

Some systems of equations don’t really fit well with graphing, substitution, or addition. The fourth and final option is a variation of the addition ...