解：解方程，此方程的解为x = 50 ∵X ： Y = X ÷ Y = Z ∴2/3 : x = 4/5 : 60 2/3 ÷ x = 4/5 ÷ 60 2/3 ÷ x = 4/5 × 1/60 2/3 ÷ x = 1/75 x = 2/3 ÷ 1/75 x = 2/3 × 75 ∴x = 50 答：此方程的解为x = 50
