分类：教育/科学-理工学科-数学
问题：9,7,5,4,用加减乘除算24，位置不能颠倒 
回答：位置不能颠倒，那么就没有答案。
下面是这个题的全部可能性：

9+(7-4)*5=24
9+((7-4)*5)=24
9+5*(7-4)=24
9+(5*(7-4))=24
(9-5)*7-4=24
((9-5)*7)-4=24
9-5*(4-7)=24
9-(5*(4-7))=24
9-(4-7)*5=24
9-((4-7)*5)=24
9*4-(7+5)=24
(9*4)-(7+5)=24
9*4-7-5=24
(9*4)-7-5=24
(9*4-7)-5=24
((9*4)-7)-5=24
9*4-(5+7)=24
(9*4)-(5+7)=24
9*4-5-7=24
(9*4)-5-7=24
(9*4-5)-7=24
((9*4)-5)-7=24
7*(9-5)-4=24
(7*(9-5))-4=24
7*4-9+5=24
(7*4)-9+5=24
(7*4-9)+5=24
((7*4)-9)+5=24
7*4-(9-5)=24
(7*4)-(9-5)=24
(7-4)*5+9=24
((7-4)*5)+9=24
7*4+5-9=24
(7*4)+5-9=24
7*4+(5-9)=24
(7*4+5)-9=24
(7*4)+(5-9)=24
((7*4)+5)-9=24
5-9+7*4=24
(5-9)+7*4=24
5-9+(7*4)=24
(5-9)+(7*4)=24
5-(9-7*4)=24
5-(9-(7*4))=24
5-9+4*7=24
(5-9)+4*7=24
5-9+(4*7)=24
(5-9)+(4*7)=24
5-(9-4*7)=24
5-(9-(4*7))=24
5+7*4-9=24
5+(7*4)-9=24
(5+7*4)-9=24
5+(7*4-9)=24
(5+(7*4))-9=24
5+((7*4)-9)=24
5*(7-4)+9=24
(5*(7-4))+9=24
5+4*7-9=24
5+(4*7)-9=24
(5+4*7)-9=24
5+(4*7-9)=24
(5+(4*7))-9=24
5+((4*7)-9)=24
4*9-(7+5)=24
(4*9)-(7+5)=24
4*9-7-5=24
(4*9)-7-5=24
(4*9-7)-5=24
((4*9)-7)-5=24
4*9-(5+7)=24
(4*9)-(5+7)=24
4*9-5-7=24
(4*9)-5-7=24
(4*9-5)-7=24
((4*9)-5)-7=24
4*7-9+5=24
(4*7)-9+5=24
(4*7-9)+5=24
((4*7)-9)+5=24
4*7-(9-5)=24
(4*7)-(9-5)=24
4*7+5-9=24
(4*7)+5-9=24
4*7+(5-9)=24
(4*7+5)-9=24
(4*7)+(5-9)=24
((4*7)+5)-9=24