This Instructional Activity is a part of the Lesson 8, Unit 6, Grade 7. The first question is straightforward since each diagram uses a different letter, but it's there to make sure students start with p(x+q)=r. If some want to rewrite as px+pq=r first, that's great. We want some to do that but others to divide both sides by p first. Monitor for students who take each approach.