SOLUTION: i need to solve using substitution. how do i go about solving this problem: 5r-s=5 -4r+5s=17

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Question 244870: i need to solve using substitution. how do i go about solving this problem:
5r-s=5
-4r+5s=17
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
solve 1st eqn for s ___ 5r - 5 = s

SUBSTITUTE into 2nd eqn ___ -4r + 5(5r - 5) = 17

-4r + 25r - 25 = 17 ___ 21r = 42 ___ r = 2

SUBSTITUTE to find s ___ 5(2) - 5 = s ___ 5 = s