Пример: (3/7-16/21)*2 1/7+(11/15+0,3): 12 2/5 - вопрос №55892213716212171115031225 от Mila672 24.05.2020 18:25

Question

Математика: Пример: (3/7-16/21)*2 1/7+(11/15+0,3): 12 2/5

Mila672 · Answer

(3/7 - 16/21) * 2 1/7 + (11/15 + 0,3) : 12 2/5 = -53/84,

1) 3/7 - 16/21 = 9/21 - 16/21 = -7/21 = -1/3,
2) -1/3 * 2 1/7 = -1/3 * 15/7 = -5/7,
3) 11/15 + 0,3 = 11/15 + 3/10 = 22/30 + 9/30 = 31/30 = 1 1/30,
4) 1 1/30 : 12 2/5 = 31/30 : 62/5 = 31/30 * 5/62 = 1/12,
5) -5/7 + 1/12 = -60/84 + 7/84= -53/84