Let one number be x, and the other number be y. x and y Their sum = 34 x + y = 34 Their difference = 10 x - y = 10 A little angel told me, the answer is 22 and 12! We have a pair of simultaneous equations and will solve these using substitution. x + y = 34 (1) x - y = 10 (2) Rearrange (2): x - y = 10 x = 10 + y (3) Substitute (3) into (1) x + y = 34 (10 + y) + y =34 10 + y + y = 34 2y = 24 y =12 (4) Substitute (4) into (3) x = 10 + y x = 10 + 12 = 22 Hence the two numbers are 12, and 22.