Выполнить действие (7/15-1/6)+2/5
(7/15 - 1/6) + 2/5 = = (14/30 - 5/30) + 2/5 = = 9/30 + 2/5 = = 3/10 + 2/5 = = 3/10 + 4/10 = 7/10
(7/15-1/6)+2/5=? ноз(15,6,5)=30 (14/30-5/30)+12/30=9/30+12/30=21/30сокращаем =7/10=0,7