{-4x+2y=-18
{-2x=y+5
2007-03-07 02:59:03 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
-4x+2y=-18
-4x = -2y -18
x = 1/2 y + 9/2 --(1)
-2x=y+5
from(1)
-2(1/2 y +9/2) = y+5
-y - 9 = y + 5
2y = -14
y = -7
Substitute into (1)
x = 1/2(-7) +9/2
x = 1
2007-03-07 03:04:25 · answer #1 · answered by seah 7 · 1⤊ 0⤋
If -2x=y+5, then double that to get ur -4x on top.
so -4x=2y+10.
(on the top equation) substitute 2y+10 for your -4x 2y+2y+10= -18
4y+10= -18 4y= -28 y=-7
(on the bottom equation) you know what y is so plug it in
-2x= -7 + 5
-2x= -2 x=1
now you have both x and y (x=1 and y= -7)
2007-03-07 11:10:48 · answer #2 · answered by seminolefan925 2 · 0⤊ 0⤋
-2x = y + 5
> y = -2x - 5 = -(2x + 5)
-4x + 2y = -18
> 4x - 2y = 18
> 4x + 2(2x + 5) = 18
> 4x +4x = 18 - 10
> x = 8/8
> x = 1
y = -(2*1 + 5)
= -7
2007-03-07 11:03:38 · answer #3 · answered by ganesan 2 · 0⤊ 0⤋
-18+4x = 2y
y=(-18+4x)/2=-9+2x
-2x=-9+2x+5
-2x-2x=-9+5
-4x=-4
x= 1
-2(1)=y+5
-2-5=y
y= -7
2007-03-07 11:10:54 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Do your own homework!!! LOL
2007-03-07 11:17:24 · answer #5 · answered by zekemarie 3 · 0⤊ 0⤋