18/40 - 12/25 tolong jawab

18/40 - 12/25 
=9/20 - 12/25      (Disamakan penyebut)
=9x5/100 - 12x4/100
=45-48/100
= -3/100

18/40 - 12/25 =
450/1.000 - 480/1.000 =
-30/1.000 =
-3/100