=2-(1÷5+1÷3)=2-8÷15=1...7÷15 (一又七分之十五,下格式同)
=(3÷4-3÷5)÷(7÷10)=(3÷20)X(10÷7)=1...13÷14
=(2÷3+2÷9)÷(20÷21)=(4÷9)X(21÷20)=14÷15
=1-(5÷14)÷(5÷7)=1-1÷2=1÷2
=(1÷4)÷(2÷3+1÷2)X(4÷5)=1÷4÷(7÷6)X4÷5=1÷7X6÷5=6÷35
=[8÷15-(4÷5-3÷10)]X15÷14=[8÷15-(1÷2)]X15÷14=1÷30X15÷14=1÷28
请采纳答案,支持我一下.