Inequalities that use < or > symbols are plotted with a dashed line to show that the line is not included in the region. Inequalities that use ≤ or ≥ symbols are plotted with a solid line to show that ...

As students filed into Jeremy Harkin’s Algebra 2 class at Schaumburg High School on a recent Thursday, he put the question of the day on the board: “What are common mistakes students make when solving ...