x-y+2z=5 2x+y-z=9 x-2y+3z=4 plissss isikan skrangg aku lupa ga ngafalinn.. itu persamaan 1.2.3

x-y+2z=5|×2|2x-2y+4z=10
2x+y-z=9|×1| 2x+y-z=9
-------------------------------------- -
-3y+5z=1............(i)

x-y+2z=5
x-2y+3z=4
--------------- -
y-z=1...................(ii)

spldv
-3y+5z=1|×1|-3y+5z=1
y-z=1|×-3|-3y+3z=-3
------------------------------- -
2z=4
z=4/2=2
◆y-z=1
y-2=1
y=1+2=3
◆x-y+2z=5
x-3+2(2)=5
x-3+4=5
x=5+3-4=4