T = 1/5(x - y + z)
First, let's get rid of the 1/5. To do this, you can multiply both sides by the reciprocal, or 5/1.
(5/1)T=[(5/1)1/5](x-y+z)
5T = x - y + z
Now subtract x from both sides.
5T - x = -y + z
Add y to both sides.
5T - x + y = z
So the answer is:
z = 5T - x + y