〔根号（5*5）〕*5－1=24
1: 5 × (5 - 1 ÷ 5) 2: 5 × (5 - (1 ÷ 5)) 3: (5 - 1 ÷ 5) × 5 4: (5 - (1 ÷ 5)) × 5
(5-1/5)*5
(5-1/5)*5=24
