z=m-x+y, for x
This is a literal equation. Let's add subtract (m + y) from each side:
z - (m + y) = m - x + y - (m + y)
The m + y terms cancel on the right side, so we have:
z - m - y = -x
Multiply each side by -1 to isolate x:
-1(z - m - y) = -(-x)
x = m + y - z
This is a literal equation. Let's add subtract (m + y) from each side:
z - (m + y) = m - x + y - (m + y)
The m + y terms cancel on the right side, so we have:
z - m - y = -x
Multiply each side by -1 to isolate x:
-1(z - m - y) = -(-x)
x = m + y - z