Understand that solutions to a system of two linear equations in two variables correspond to points of intersection of their graphs, because points of intersection satisfy both equations simultaneously.
Solve systems of two linear equations in two variables algebraically, and estimate solutions by graphing the equations. Solve simple cases by inspection. For example, 3x + 2y = 5 and 3x + 2y = 6 have no solution because 3x + 2y cannot simultaneously be 5 and 6.
Today's Warmup reviews the previous day's material.
Warm-up problems also sometimes extend lessons that students have encountered before to more unfamiliar contexts. For a video narrative about how I structure each lesson, and how the warm-up fits in, click here.