7,9,2,1,算24点!3种
4个回答

7+((9*2)-1)

(7+(9*2))-1

7+((2*9)-1)

(7+(2*9))-1

((7*2)+9)+1

(7*2)+(9+1)

((7*2)+1)+9

(7*2)+(1+9)

7-(1-(9*2))

(7-1)+(9*2)

7-(1-(2*9))

(7-1)+(2*9)

9+((7*2)+1)

(9+(7*2))+1

9+((2*7)+1)

(9+(2*7))+1

((9*2)+7)-1

(9*2)+(7-1)

(9*2)-(1-7)

((9*2)-1)+7

9+(1+(7*2))

(9+1)+(7*2)

9+(1+(2*7))

(9+1)+(2*7)

((2*7)+9)+1

(2*7)+(9+1)

((2*7)+1)+9

(2*7)+(1+9)

((2*9)+7)-1

(2*9)+(7-1)

(2*9)-(1-7)

((2*9)-1)+7

1+((7*2)+9)

(1+(7*2))+9

1+(9+(7*2))

(1+9)+(7*2)

1+(9+(2*7))

(1+9)+(2*7)

1+((2*7)+9)

(1+(2*7))+9