kak tolong jawab Sistem Persamaan Linear 3 Variabel x+3y-z=4 x+2y-3z=7 x+y-z=2

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

persamaan (1) & (2)
x+3y-z=4
x+2y-3z= 7
_________ _
y+2z = -3 --------> (4)

persamaan (2) & (3)
x+2y-3z = 7
x+y-z = 2
__________ _
y-2z = 5 ------------> (5)

persamaan (4)&(5)
y+2z = -3
y-2z = 5
_______ _
4z = -8
z = -2

persamaan (4)
y + 2z = -3
y -4 = -3
y = 1

persamaan (3)
x + y - z = 2
x + 1 +2 = 2
x + 3 = 2
x = -1

jadi x= -1 , y= 1 , z= -2