А)7/9-5/18 б)14/25-1/5. в)7/10-9/100. г)7/11 -21/44
7/9-5/18= 14/18-5/18=9/18=1/2 14/25-1/5 = 14/25- 5/25=9/25 7/10-9/100= 70/100-9/100=61/100 7/11-21/44= 28/44-21/44= 7/44