1: If a / b = C / D = E / F = 2 / 5, find the conclusion of (1) (A-C) / (B-D); (2) (2a + 3c-4e) / (2B + 3d-4f) (3) comparison, and find what rule

1: If a / b = C / D = E / F = 2 / 5, find the conclusion of (1) (A-C) / (B-D); (2) (2a + 3c-4e) / (2B + 3d-4f) (3) comparison, and find what rule

Let m = 2 / 5 (because 2 / 5 is too cumbersome to write, there is no other meaning) a / b = m, so a = BM, C = DM, e = FM (1) (A-C) / (B-D) = (BM DM) / (B-D) = m (B-D) / (B-D) = M = 2 / 5 (2) (2a + 3c-4e) / (2B + 3d-4f) = (2bm + 3dm-4fm) / (2B + 3d-4f) = m (2B + 3d-4f) / (2B + 3d-4f) =