Me plz with 3 and 4 plz and show me how bacouse i need to write it down ! but

3.= 37/4 − 16/5
= ((37 × 5) − (16 × 4)) / (4 × 5) 
= (185 - 64) / 20
= 121/20
= 121/20
= 6 1/20
Convert the mixed numbers into fractions.
Use the algebraic formula for subtraction of fractions: a/b - c/d = (ad - bc) / bd.
4.
= 57/20
= 2  17/20
The formula for subtracting fractions is a/b - c/d = (ad - bc) / bd.

Deductive reasoning!!!