CHECKLIST for Solving a System of Equations | 8.EE.C.8

In this math video we will create and use a checklist for solving a system of equations. Checklist Step 1: If necessary, solve one of the equations for one of the two variables. Step 2: Substitute the expression from Step 1 into the other equation. Step 3: Solve the equation you created in Step 2. Step 4: Substitute the solution from Step 3 into the equation from Step 1 to solve for the other variable. Step 5: Check! We will understand that Step 1 is not necessary, however, we will still identify the expression that one variable is equivalent to. In step 2, we will substitute the expression we identified in step 1 for the variable in the second equation. This will create ONE equation with one variable. For step 3, we will solve the equation by collecting variable terms to one side using inverse operations. We will find the value of one variable. Step 4 will have us evaluate one of the original equations using the variable value from step 3. This will provide us with the value of the second variable. Step 5 will be where we check our solutions to be sure they make BOTH equations true. We will conclude our work by answering the question which asks for the value of one of the variables. An exemplar solution is modeled and explained.