当a=0.6,b=—3.2,c=一又三分之二（请原谅我不会用数字打……）

先化简
a=3/5 b= -16/5 c=5/3
[1]
3/5 * (-16/5) - 5/3
=-48/5 - 5/3
=-144/75 - 125/75
=-269/75
[2]
(5/3+16/5)/(3/5)
=73/15 / 3/5
=73/9
[3]
3(3/5 - 5/3 - 16/5) / -16/5
=(5/9 - 5 - 48/5) / -16/5
=-9/16 + 25/16 + 3
=1+3
=4