30又28分之1×29分之28
=(30+1/28)X28/29
=30X28/29+1/28X28/29
=(29+1)X28/29+1/29
=28+28/29+1/29
=28+1
=29
9分之2-16分之7×9分之2
=2/9-7/16*2/9
=2/9*(1-7/16)
=2/9*9/16
=1/8
30又28分之1×29分之28
=(30+1/28)X28/29
=30X28/29+1/28X28/29
=(29+1)X28/29+1/29
=28+28/29+1/29
=28+1
=29
9分之2-16分之7×9分之2
=2/9-7/16*2/9
=2/9*(1-7/16)
=2/9*9/16
=1/8