Answer:
x-y/2z=3
2z(x-y)/2z = 3 × 2z
x-y = 6z
x-y/6 = 6z/6
z = x-y/6
x-y/2z = 3
x - y = 6z
x-y+y = 6z + y
x = 6z + y
-x + x - y = 6z - x
-y = 6z - x
-y/-1 = 6z - x / -1
y = -6z + x