Answer:
x = -1, y = 7 , z = 5.
Step-by-step explanation:
-7x - 2y + z = -2 .........(1)
6x - y - z = -18........(2)
5x + 4y - z= 18..........(3)
Subtract equations (2) - (3):
x - 5y = -36.........(4)
Add equations (1) and (2):
-x - 3y = -20.......(5)
Adding (4) and (5):
-8y = -56
y = 7.
Substitute y = 7 into equation 4:
x - 5(7) = -36
x - 35 = -36
x = -1.
Substitute x = -1 and y = 7 in equation (1):
-7(-1) - 2(7) + z = -2
7 - 14 + z = -2
z = -2 - 7 + 14
z = 5.
