Question 228347
x=z-4 0r x-z=4
x+z=2y
x+y+z=24
Replace (x+z) with 2y
2y+y=24
3y=24
y=24/3
y=8 ans.
x+z=2*8
x+z=16
x-z=4 add these 2 equations.
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2x=20
x=20/2
x=10 ans.
10-z=4
-z=4-10
-z=-6 
z=6ans.
Proof:
8+10+6=24
24=24