(ただし1と2を合せて12のような使い方は出来ません。)
18個の解法が見つかりました。
((2×7)-(9-5))=10
((5+(2×7))-9)=10
((5-9)+(2×7))=10
(5+((2×7)-9))=10
(5-(9-(2×7)))=10
(7+(9÷(5-2)))=10
(7-(9÷(2-5)))=10
(9+((2+5)÷7))=10
(9+((7-2)÷5))=10
(9+((7-5)÷2))=10
(9+(2÷(7-5)))=10
(9+(5÷(7-2)))=10
(9+(7÷(2+5)))=10
(9-((2-7)÷5))=10
(9-((5-7)÷2))=10
(9-(2÷(5-7)))=10
(9-(5÷(2-7)))=10