1(1/2)等于3/2 它的倒数就是3/2,分子和分母相反倒过了,所以等于2/3
5/9+7/8=40/72+63/72=108/72
7/12 x2/3=7/12x8/12=56/12=4(2/3)
7/9 /5/8=7/9除5/8=35/45x72/45=2520/45=56
5/12-7/9=45/108-84/108=-(39/108)=-4(7/80)
7/16倒数为16/7
3/7倒数为7/3
1(5/9)=14/9倒数为9/14等
1(1/2)等于3/2 它的倒数就是3/2,分子和分母相反倒过了,所以等于2/3
5/9+7/8=40/72+63/72=108/72
7/12 x2/3=7/12x8/12=56/12=4(2/3)
7/9 /5/8=7/9除5/8=35/45x72/45=2520/45=56
5/12-7/9=45/108-84/108=-(39/108)=-4(7/80)
7/16倒数为16/7
3/7倒数为7/3
1(5/9)=14/9倒数为9/14等