(4分之1+6分之5-3分之2)乘12
=1/4*12+5/6*12-2/3*12
=3+10-8
=5
24乘5分之2+75除2.5+0.4
=24*0.4+75*0.4+0.4*1
=(24+75+1)*0.4
=100*0.4
=40
(4又8分之7+16分之13)除16分之13
=(4又7/8+13/16)*16/13
=39/8*16/13+13/16*16/13
=6+1
=7
(4分之1+6分之5-3分之2)乘12=3+10-8=5
24乘5分之2+75除2.5+0.4=0.4(24+1)+30=10+30=40
(4又8分之7+16分之13)除16分之13=(64+14+13)/13=91/13=7