（ただし１と２を合せて１２のような使い方は出来ません。）
42個の解法が見つかりました。
((1+5)+(7-3))=10
((1+5)-(3-7))=10
((1+7)+(5-3))=10
((1+7)-(3-5))=10
((1-3)+(5+7))=10
((5×(7-1))÷3)=10
((5+(1+7))-3)=10
((5+7)+(1-3))=10
((5+7)-(3-1))=10
((5-3)+(1+7))=10
((5÷3)×(7-1))=10
((7+(1+5))-3)=10
((7-1)×(5÷3))=10
((7-1)÷(3÷5))=10
((7-3)+(1+5))=10
(1+((5+7)-3))=10
(1+(5+(7-3)))=10
(1+(5-(3-7)))=10
(1+(7+(5-3)))=10
(1+(7-(3-5)))=10
(1-((3-5)-7))=10
(1-((3-7)-5))=10
(1-(3-(5+7)))=10
(5×((7-1)÷3))=10
(5+((1+7)-3))=10
(5+(1+(7-3)))=10
(5+(1-(3-7)))=10
(5+(7+(1-3)))=10
(5+(7-(3-1)))=10
(5-((3-1)-7))=10
(5-((3-7)-1))=10
(5-(3-(1+7)))=10
(5÷(3÷(7-1)))=10
(7+((1+5)-3))=10
(7+(1+(5-3)))=10
(7+(1-(3-5)))=10
(7+(5+(1-3)))=10
(7+(5-(3-1)))=10
(7-((3-1)-5))=10
(7-((3-5)-1))=10
(7-(3-(1+5)))=10