How do you solve the following system?: 1/2x=y-1 , -x+3y=-7 12x=y1,x+3y=7

1 Answer
Apr 24, 2018

x=-20x=20

y=-9y=9

Explanation:

The given equations are

1/2x = y-112x=y1
-x+3y = -7x+3y=7

From 1/2x = y-112x=y1

x=2(y-1)x=2(y1)

Substituting this xx value in equation -x+3y = -7x+3y=7

=> - (2(y-1) + 3y = -7(2(y1)+3y=7

=> -2y +2 +3y = -72y+2+3y=7

=> y+2 = -7y+2=7

=> y= -7-2y=72

=> y = -9y=9

Substitute this yy value in any of the given equations to obtain the xx value

-x +3y = -7x+3y=7

=> -x + 3(-9) = -7x+3(9)=7

=> -x -27 = -7x27=7

=> x = -20 x=20