Solve for r. -pr + r = 8r - 2

Pls! does anybody know a shortcut for answering these types of questions in the future?

We have enough material to build a fence around a station that has a perimeter of 180 feet the width of the rectangular space must be 3 1/4 feet what must the length be

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?