SOLUTION: Solve using the elimination method 7r-3s=15 3r+7s=81

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Question 284433: Solve using the elimination method
7r-3s=15
3r+7s=81
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.7r-3s=15
2.3r%2B7s=81
Multiply eq. 1 by 7 and eq. 2 by 3 and add.
49r-21s%2B9r%2B21s=105%2B243
58r=348
r=6
Then from eq. 1,
7r-3s=15
42-3s=15
3s=42-15
3s=27
s=9