x + y = 16, and x - y = 12. Get x by itself. Subtract y from both sides in the 1st equation to get x = 16 - y. Add y to both sides in the 2nd equation to get x = 12 + y. Put the parts together. 16-y=12+y. Add y to both sides to get 16 = 12 + 2y. Subtract 12 to get 4 = 2y. Divide both sides by 2 to get y = 2. Replace it with the 1st equation to get X + 2 = 16. Subtract 2 from both sides to get X = 14.
