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Loren pointed you in the right direction. I don't see that you ever did anything with Loren's guidance. It appears that you simply keep posting more exercises.
At this point, I can't even determine with which exercises you still need help, let alone the types of guidance that you need.
Please start a new thread for each new exercise.
When somebody responds, then post a reply either to show us your work or to ask questions about that which you still don't understand.
Did you factor the expression 72r + 16s ?
?