Tolong bantu nomor 2&3 tentang Sistem Persamaan liner 2 variabel meotde subtitusi

2. 2x+y=12
x- y = 3
__________+
3x=15
x=5

x-y=3 |2| 2x-2y=6
2x+y=12 |1|2x+y=12
______________-
-y=-6 HP {5,-6}


3. 2x+3y=8 |5| 10x +15y=40
x+ 5y=11 |3| 3x+15y =33
_________________-
7x=7
x=1

2x+3y=8 |1| 2x+3y=8
x+5y=11 |2| 2x+10y=22
____________________-
-7y=-14
y= 2 HP{1,2}

semoga membantu...
maaf kalo salah :)