This Problem Set is a part of the Lesson 3, Unit 4, Grade 8. Understand and explain why you can add, subtract, multiply, and divide each side of an equation by an expression involving rational numbers and still have an equivalent equation (as long as you don't divide by 0). Let's rewrite equations while keeping the same solutions. Learning targets: students can add, subtract, multiply, or divide each side of an equation by the same expression to get a new equation with the same solution.