Answer:
x=2
y=-1
z=3
Step-by-step explanation:
X = 7+2y-z
3(7+2y-z)+y-z=2
21+6y-3z+y-z=2
21+7y-4z=2
7y-4z=-19 (subtract both side by 21)
2(7+2y-z)+3y+2z=7
14+4y-2z+3y+2z=7
14+7y=7
7y=-7 (subtract both side by 14)
y=-1 (divide both side by 7)
{7y-4z=-19
{y=-1
7.-1 - 4z=-19
-7-4z=-19
-4z=-12
Z=3
x=7+2y-z (y=-1 z=3)
x=7+2.-1 - 3
x=7-2-3
x=2
