(ただし1と2を合せて12のような使い方は出来ません。)
32個の解法が見つかりました。
((5+5)×(9÷9))=10
((5+5)+(9-9))=10
((5+5)-(9-9))=10
((5+5)÷(9÷9))=10
((5+9)+(5-9))=10
((5+9)-(9-5))=10
((5-9)+(5+9))=10
((9×(5+5))÷9)=10
((9+(5+5))-9)=10
((9-9)+(5+5))=10
((9÷9)×(5+5))=10
(5+((5×9)÷9))=10
(5+((5+9)-9))=10
(5+(5×(9÷9)))=10
(5+(5+(9-9)))=10
(5+(5-(9-9)))=10
(5+(5÷(9÷9)))=10
(5+(9×(5÷9)))=10
(5+(9+(5-9)))=10
(5+(9-(9-5)))=10
(5+(9÷(9÷5)))=10
(5-((9-5)-9))=10
(5-((9-9)-5))=10
(5-(9-(5+9)))=10
(9×((5+5)÷9))=10
(9+((5+5)-9))=10
(9+(5+(5-9)))=10
(9+(5-(9-5)))=10
(9-((9-5)-5))=10
(9-(9-(5+5)))=10
(9÷(9÷(5+5)))=10