本题答案不唯一. 4X9-5-7=24 4X7-9+5=24 (7-4)X5+9=24
9+(7-4)*5=24 (9-5)*7-4=24 9-5*(4-7)=24 9*4-(7+5)=24 7*4-(9-5)=24
4*9-7-524
9×4-7-5=24
4×9-7-5=36-11=24
