一个分数的分子扩大4倍,分母缩小2倍,这个数的值就扩大8倍. .
4:5==20: = %
3÷8==24: = %.
0.2: == ﹣== %
0.6: =9.6÷ =1.2= %.
0.75=3÷ = :16== %