5th CaMO 1973 Problem 2 Find all real numbers x such that x + 1 = |x + 3| - |x - 1|.
If x ≥ 1, then x+1 = x+3 - (x-1) = 4, so x = 3. If -3 ≤ x < 1, then x+1 = (x+3) - (1-x) = 2x+2, so x = -1. If x < -3, then x+1 = -(x+3) - (1-x) = -4, so x = -5. 5th CaMO 1973 © John Scholes jscholes@kalva.demon.co.uk 10 June 2002