1. -3x-6y=30

1. Eliminasikan X
-3x-6y=30 |x2| -6x-12y=60
2x+5y=27 |x3| 6x+15y=81

-6x-12y=60
6x+15y=81 +
—————–
0x+3y=141
y=141/3
y=47

2. Substitusikan Y
-3x-6y=30 (semua dibagi 6)
—————:6
-1/2x-y=5
-y=5+1/2x
y=-5-1/2x

2x+5y=27
2x+5(-5-1/2x)=27
2x-25-5/2x=27
2x-5/2x=27+25
4/2x-5/2x=52
-1/2x=52
x=52x(-2)
x=-104

pembuktian
2x+5y=27
2(-104)+5(47)=27
-208+235=27
27=27 (terbukti)