SOLUTION: 21. 3X-2Y+-13 9X+5Y=16 I tried to solve this equation using the the process of elimination by addition method. I know I am surpose to use the lcm which i did for 3x and 9x

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: 21. 3X-2Y+-13 9X+5Y=16 I tried to solve this equation using the the process of elimination by addition method. I know I am surpose to use the lcm which i did for 3x and 9x       Log On


   



Question 62487This question is from textbook beginning algebra
: 21. 3X-2Y+-13
9X+5Y=16
I tried to solve this equation using the the process of elimination by addition method. I know I am surpose to use the lcm which i did for 3x and 9x the lcm would be 18 by using this method I still came up with the wrong answer the book has (1,5) can you tell me what I am doing wrong? thanks
This question is from textbook beginning algebra

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
1st: 3X-2Y=-13
2nd: 9X+5Y=16
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Multiply 1st by 3 to get:
3rd: 9x-6y=-39
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Subtract 3rd from 2nd to get:
11y=55
y=5
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Substitute into 1st to solve for x, as follows:
3x-2(5)=-13
3x=-3
x= -1
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Final solution:
x=-1, y=5
Cheers,
Stan H.