Respuesta :

get a common denominator.

3/4.. multiply the numerator and denominator by 5.
3/4 × 5 = 15/20
2/5.. multiply the numerator and denominator by 4.
2/5 × 4 = 8/20
subtract
15/20 - 8/20 = 7/20
the answer is 7/20 because you cannot simplify it.
RELAXING NOICE
Relax