SOLUTION: find the solution to each system by the addition elimination method 5s+ 9t= 6 4s- 3t= 15

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Question 751548: find the solution to each system by the addition elimination method 5s+ 9t= 6 4s- 3t= 15
Found 2 solutions by timvanswearingen, kmadison:
Answer by timvanswearingen(106) About Me  (Show Source):
You can put this solution on YOUR website!
Multiply the second equation by 3, the result is:
12s-9t=45
Now line up this equation and the first equation and add them up by adding like terms, the result will be:
17s=51
Divide both sides by 17:
s=3
Now plug in 3 for s, in any equation used in the problem. I'll use the first equation:
5s%2B9t=6
5%283%29%2B9t=6
15%2B9t=6
Subtract 15:
9t=-9
Divide by 9:
t=+-1

Answer by kmadison(20) About Me  (Show Source):
You can put this solution on YOUR website!
5s + 9t = 6
4s - 3t = 15
Multiply 2nd equation by 3 --> 12s - 9t = 45
Now add to 1st
5s + 9t = 6
+(12s - 9t = 45)
-----------------
17s = 51
s = 3
Plug s = 3 into original 2nd equation:
4(3) - 3t = 15 --> 12 - 3t = 15
-3t = 3
t = -1
FINAL ANSWER: s = 3, t = -1