Answer: See below
Explanation:
4x + 4y + z = 24 (1)
2x - 4y + z = 0 (2)
5x - 4y - 5z = 12 (3)
Add (1) and (2):
4x + 4y + z = 24
2x - 4y + z = 0
————————
6x + 2z = 24 (4)
Add (1) and (3):
4x + 4y + z = 24
5x - 4y - 5z = 12
————————-
9x - 3z = 36 (5)
Add (4) and (5):
3(6x + 2z = 24)
2(9x - 3z = 36)
————————
18x + 6z = 72
18x - 6z = 72
———————-
36x = 144
x = 144/36
x = 4
Plug x value in (4):
6(4) + 2z = 24
24 + 2z = 24
2z = 0
z = 0
Plug x and z value in (2):
2(4) - 4y + 0 = 0
8 - 4y + 0 = 0
-4y = -8
y = -8/-4
y = 2
Therefore, x = 4, y = 2 and z = 0
