You can access the answers to Marcy Mathworks' Punchline Algebra series and Mathimagination by going to the back of the textbooks themselves. You can purchase the textbooks from the Marcy Mathworks website in order to access the answer keys. Many of the individual lessons also provide answers to the problems therein.
To locate the answers at the back of the textbooks, go to a textbook Table of Contents to see the page numbers for the complete answer sections, which may also have extras for teachers.
The design of the Marcy Mathworks textbooks enables you to discover the answers as you solve the problems. Many of the problems take the form of a game or riddle, and you have to solve the correct answers in order to uncover the riddle or question answers. If the riddle answer is wrong (such as in spelling), you then know that you made a mistake, whereas the correct riddle answer means the problem set was completed accurately. Answers may come in the form of scrambled answer lists or codes.
Some of the problems enable you and another student to work together towards an answer. If the problem is not solved, the teacher can then consult the answer key at the back of the book.