Discovery Education
Discovery Education: Web Math: Solve a Linear Equation Involving One Unknown
This WebMath site explains how to enter your equation with one variable and solve for that variable. It explains step-by-step how to solve the equations and gives the final solutions.
Illustrative Mathematics
Illustrative Mathematics: A Rei Reasoning With Linear Inequalities
Students are presented with a solution to an inequality and are asked to find two mathematical errors and explain why they are incorrect. Aligns with A-REI.B.3 and A-REI.A.1.