0.75x﹣0.75y=(x﹣y)(0.75﹣0.75) (判断对错)改正: .
:20==24÷ = %=二成= 折.
:8=== %
4÷ = =0.25= :40= %.
÷10==4:5= (填小数)= %.
=0.75=21: = %.