solve this system of equations using the linear combination method

-3x+12y=-27
5x+20y=15

1 answer

commonly called the elimination method

I would multiply the first by 5
---> -15x + 60y = - 135
multiply the 2nd by 3
---> 15x + 60y = 45
add them:
120y = - 90
y = -90/120 = -3/4

sub that into either of the two originals to get the x