Prove that if x and y are real numbers, then max(x, y) + min(x, y) = x + y.

[Hint: Use a proof by cases, with the two cases corresponding to x ≥ y and x < y, respectively.]

Prove that if x and y are real numbers, then max(x, y) + min(x, y) = x + y.

[Hint: Use a proof by cases, with the two cases corresponding to x ≥ y and x < y, respectively.]