3 per 4 dikurang 3 per 5

3/4 -3/5 =
15/20 - 12/20= 3/20

[tex] \frac{3}{4} - \frac{3}{5} = \frac{15 - 12}{20} = \frac{3}{20} [/tex]

Hopefully this is the best for you :)