(ただし1と2を合せて12のような使い方は出来ません。)
20個の解法が見つかりました。
(((9+9)-5)-3)=10
((9+(9-3))-5)=10
((9+(9-5))-3)=10
((9+9)-(3+5))=10
((9-(3-9))-5)=10
((9-(5-9))-3)=10
((9-3)+(9-5))=10
((9-3)-(5-9))=10
((9-5)+(9-3))=10
((9-5)-(3-9))=10
(5×(3-(9÷9)))=10
(9+((9-3)-5))=10
(9+((9-5)-3))=10
(9+(9-(3+5)))=10
(9-((3+5)-9))=10
(9-(3+(5-9)))=10
(9-(3-(9-5)))=10
(9-(5+(3-9)))=10
(9-(5-(9-3)))=10