bantuin ini dong please!

x-2y+3z=10 ×2
2x+3y-z=-1 ×1

2x-4y+6z=20
2x+3y-z =-1
--------------------- -
-7y+7z=21 (1)

2x+3y-z=-1
2x+y-2z=11
-------------------- -
2y+z=-12 (2)
persamaan 1 dan 2
-7y+7z=21 ×1
2y+z =-12 ×7

-7y+7z=21
14y+7z=-84
------------------- -
-21y =105
y =-5

masukkan ke persamaan 2
2y+z=-12
2.-5+z=-12
-10+z=-12
z=-12+10
z=-2

×-2y+3z=10
x-2.-5+3.-2=10
x+10-6 =10
x+4 =10
x =10-4
x=6
jadi x=6,y=-5,z=-2