Answer :
3/4 = 7.5/10
--------------------
Therefore:
3/4 - 3/10
= 7.5/10 - 3/10
= 4.5/10
= 0.45
= 9/20
--------------------
Therefore:
3/4 - 3/10
= 7.5/10 - 3/10
= 4.5/10
= 0.45
= 9/20