Solve for both systems: 8x+y=129 and 9x + 4y = 171

Asked by AnneS2 on 20 Sep 05:51

Last updated by anonymous on 21 Sep 16:17

Answered by CherieS on 21 Sep 16:17

8x+y=129

8x-8x+y=129-8x

y=129-8x

9x + 4y = 171

9x + 4(129-8x) = 171

9x + 4(129) (4)(-8x) = 171

9x + 516 -32x = 171

516 -23x = 171

516 -23x -516= 171-516

-23x=-345

-23x/-23=-345/-23

x=15

y=129-8x

y=129-8(15)

y=129-120=9