SOLUTION: Solve by using the multiplication principal and then add: 7p+5q=4 8p-9q=17 I can not for the life of me figure out how to get one of these to cancel out so that I can elimin

Question 251529: Solve by using the multiplication principal and then add:
7p+5q=4
8p-9q=17
I can not for the life of me figure out how to get one of these to cancel out so that I can eliminate it by using the multiplication principal first...i started by multiplying the first equation by 2 but that doesn't seem to work...so im not sure if i an doing this right...thanks :)
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
either multiply the first by 8 and the second by 7 and subtract the two new equations
or multiply the first by 9 and the second by 5 and add the two new equations

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