9分之4除以6+9分之5*6分之1
=4/9*1/6+5/9+1/6
=1/6*(4/9+5/9)
=1/6*1
=1
12*(1-3分之2除以4分之3)
=12*(1-2/3*4/3)
=12*(1-8/9)
=12*1/9
=4/3
(26分之21*7分之13+2分之1)除以5分之2
=(21/26*13/7+1/2)*5/2
=(3/2+1/2)*5/2
=2*5/2
=5
9分之8*[4分之3-(16分之7-4分之1)]
=8/9*(3/4-7/16+1/4)
=8/9*(1-7/16)
8/9*9/16
=1/2