This Instructional Activity is a part of the Lesson 15, Unit 5, Grade 7. Students solved equations of the form x+p = q and px=q in grade 6, but the equations only involved positive values. This activity bridges their understanding of a solution to an equation as a value that makes the equation true with their understanding of operations involving negative numbers from this unit. This activity builds on the work students have done in this lesson evaluating expressions at different values. Monitor for students who: take an arithmetic approach by substituting in values and evaluating.