12分之7*11+12分之7
=7/12x(11+1)
=7/12x12
=7
8分之7*49分之3*9分之8
=7/8x8/9x3/49
=7/9x3/49
=1/21
35*(4分之1+3分之1)
=(36-1)x(3/12+4/12)
=36x7/12-1x7/12
=21-7/12
=20又5/12
12分之7*11+12分之7
=7/12x(11+1)
=7/12x12
=7
8分之7*49分之3*9分之8
=7/8x8/9x3/49
=7/9x3/49
=1/21
35*(4分之1+3分之1)
=(36-1)x(3/12+4/12)
=36x7/12-1x7/12
=21-7/12
=20又5/12