115 = 5*23
85 = 5*17
Наименьший общий знаменатель :
НОЗ (115,85) = 115 * 17 = 1995
19/115 = (19*17)/(115*17) =323/1995
11/85 = (11*23)/ (85 * 23) = 253/1995
323/1995 > 253/1995 ⇒ 19/115 > 11/85
НОЗ (15,14) = 15 * 14 = 210
7/15 = (7*14)/(15*14) = 98/210
5/14 = (5*15)/(14 * 15) = 75/210
98/210 > 75/210 ⇒ 7/15 > 5/14