Б)

14/25 - 1/5 = (145)/(255) - 5/25
= 70/125 - 25/125
= (70-25)/125
= 45/125
= 9/25

в)

7/10 - 9/100 = (710)/(1010) - 9/100
= 70/100 - 9/100
= (70-9)/100
= 61/100