Below is a video (and follow-up activity) that I created for my 8th graders last year. Your HW tonight is to watch the video and try your best to complete the follow-up activity that appears at the end. The purpose is to develop the third and final method for solving “systems of equations”: solving systems by elimination.
For reference, here are the videos I made for solving systems by graphing and solving systems by substitution. This may be a nice way to re-learn the material if you feel you’ve missed something over the past few classes. This is not required homework (but you should do it anyway).