Answer:
You can only add or subtract fractions that have THE SAME DENOMINATOR.
If the two fractions do not have the same denominator :
they must be REDUCED TO THE SAME DENOMINATOR.
common denominator: (4*5)= 20
3/4 =(3*5)/(4*5)= 15/20
2/5 =(2*4)/(5*4)= 8/20
15/20 - 8/20 = 7/20
the fraction equivalent to 3/4-2/5 = 7/20
Explanation: