一条路长a千米,第一天修了全长的,第二天修了全长的20%,剩下 千米没修.
== = ÷9=44÷ .
3÷4=9: == (填小数).
7÷9== ÷ 15=31÷ .
:20==3: =0.75= %
0.125== :16=5÷ .