Simplifying z + 18 = y Reorder the terms: 18 + z = y Solving 18 + z = y Solving for variable 'z'. Move all terms containing z to the left, all other terms to the right. Add '-18' to each side of the equation. 18 + -18 + z = -18 + y Combine like terms: 18 + -18 = 0 0 + z = -18 + y z = -18 + y Simplifying z = -18 + y