cara dan hasil 4/5 kurang 40persen

4/5-40%
4/5-4/10
8/10-4/10
4/10=0,4=40%

4/5 - 40/100
=> 4/5 - (40:20)/(100:20)
=> 4/5 - 2/5
=> (4 - 2)/5
=> 2/5