Сократите дроби 15/36, 42/45 , 25/100, 9/30 а потом приведите их к знаменателю 60
15/36 = 5/12; 42/45 = 14/15; 25/100 = 1/4; 9/30 = 3/10 5/12 = 25/60; 14/15 = 56/60; 1/4 = 15/60; 3/10 = 18/60