Question

One positive integer is 5 less than twice another. The sum of their squares is 725. Find the integers.

Answer 1

Let the numbers are a and b; a - 5 = 2b, and -------------- (1)a2 + b2 = 250 ----------------(2) rewriting and squaring of (1) is given as; a2 = 4b2 + 20b + 25 -------- (3) substituting (3) into (2) (4b2 + 20b + 25) + b2 = 250, thus 5b2 + 20b - 225 = 0 by dividing both sides by 5 b2 + 4b - 45 = 0 solving the quadratic for b, we will get b = -9 or 5, substituting these for b in (1), we will get a asa = -13 or 15 However, if a and b must be positive integer, then a = 15 and b = 5 is the answer