4,5,7,2的24点答案：1:(4 × (5 + 7)) ÷ 22:4 × (5 + 7) ÷ 23:4 × ((5 + 7) ÷ 2)4:(4 × (7 + 5)) ÷ 25:4 × (7 + 5) ÷ 26:4 × ((7 + 5) ÷ 2)7:(4 - 2) × (5 + 7)8:4 ÷ 2 ×(5 + 7)9:(4 ÷ 2) × (5 + 7)...