列式计算
(1) 1/2除16与3/8的差,所得的商减去4.8,得多少?
(16-3/8)/(1/2)-4.8
=(125/8)/(1/2)-4.8
=125/4-4.8
=31.25-4.8
=26.45
(2) 比60的42%多2的数是80的百分之几?
[(60*42%+2)/80]*100%
=(27.2/80)*100%
=31.5%
解方程
5/6×1/2-x=5/18
5/12-x=5/18
15-36x=10
36x=5
x=5/36
2x-45%=31
2x-0.45=31
2x=31.45
x=15.725