Решите 30 ! (по действиям) а) (7/15+7/30+4/5): - вопрос №30715730452131216110115351313833691 от nikkun80 04.04.2020 21:35

Question

Математика: Решите 30 ! (по действиям) а) (7/15+7/30+4/5): (2-1/3-1/2) б) (1/6+1/10+1/15): (3/5-1/3-1/4)

nikkun80 · Answer

А) (7/15 + 7/30 + 4/5) : (2 - 1/3 - 1/2) = 1 2/7
1) 7/15 + 7/30 = 14/30 + 7/30 = 21/30 = 7/10
2) 7/10 + 4/5 = 7/10 + 8/10 = 15/10 = 1 5/10
3) 2 - 1/3 = 1 3/3 - 1/3 = 1 2/3
4) 1 2/3 - 1/2 = 1 4/6 - 3/6 = 1 1/6
5) 1 5/10 : 1 1/6 = 15/10 : 7/6 = 15/10 * 6/7 = 45/35 = 1 10/35 = 1 2/7

б) (1/6 + 1/10 + 1/15) : (3/5 - 1/3 - 1/4) = 20
1) 1/6 + 1/10 = 5/30 + 3/30 = 8/30 = 4/15
2) 4/15 + 1/15 = 5/15 = 1/3
3) 3/5 - 1/3 = 9/15 - 5/15 = 4/15
4) 4/15 - 1/4 = 16/60 - 15/60 = 1/60
5) 1/3 : 1/60 = 1/3 * 60/1 = 60/3 = 20