SOLUTION: (1)solve for y in 3x+7y = 6x+1 (2)solve the system of equation: 2x+5y =2 -7x+4y =20

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Question 698569: (1)solve for y in 3x+7y = 6x+1
(2)solve the system of equation: 2x+5y =2
-7x+4y =20

Answer by sofiyac(983) About Me  (Show Source):
You can put this solution on YOUR website!
One problem at a time please.
(1)solve for y in 3x+7y = 6x+1
3x+7y = 6x+1 subtract 3x from each side of the equal sign
7y=3x+1 divide each side by 7
y=%283x%2B1%29%2F7
(2)solve the system of equation:
2x+5y =2
-7x+4y =20
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2x+5y =2 multiply this equation by 7
-7x+4y =20 multiply this equation by 2
14x+35y=14
-14x+8y=40 now add the two equations
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43y=54 divide both sides by 43
y=54%2F43 now plug that into either of the original equations, i'll use first one, and solve for x
2x%2B5%2854%2F43%29=2
2x%2B270%2F43=2 subtract 270/43 from each side
2x=86%2F43-270%2F43
2x=%2886-270%29%2F43
2x=%28-184%29%2F43 divide each side by 2
x=%28-184%29%2F86=-92%2F43