x = 5y, where x > 0 and y > 0; x - y = 200 => 5y - y = 200 => 4y = 200 => y = 200/4 => y = 50 => x = 250.
The smaller number is 50, and the larger number is 250. This is derived from the conditions that one number is five times another and their difference is 200.
;