Given the function y = y1-y2, where Y1 and X are in positive proportion, Y2 and X are in inverse proportion, and when x = 1, y = 1; when x = 3, y = 5

Given the function y = y1-y2, where Y1 and X are in positive proportion, Y2 and X are in inverse proportion, and when x = 1, y = 1; when x = 3, y = 5

(1) Let Y1 = K1X (K1 ≠ 0), y2 = k2x (K2 ≠ 0), ∵ y = k1x-k2x. ∵ when x = 1, y = 1. When x = 3, y = 5, ∵ K1 − K2 = 13k1 − K23 = 5, ∵ K1 = 74k2 = 34, ∵ y. The analytic expression of X function is y = 74x + 34x; (2) from (1), y = 74x + 34x. Then when x = 2, y = 74 × 2 + 38 = 318