Решите , умоляю. 1) 2 3/4 - 1 5/6 = ? 2) 4 2/15 - вопрос №309283412341562421535637512158 от viktordemi2015 24.07.2020 01:46

Question

Математика: Решите , умоляю. 1) 2 3/4 - 1 5/6 = ? 2) 4 2/15 + 3 5/6 = ? 3) 7 5/12 - ( 1 5/8 + 2 1/24 ) = ? 20 б.

viktordemi2015 · Answer

1) 2 3/4 - 1 5/6 = 11/4 - 11/6 = (11*3 - 11*2)/12 = (33 - 22)/12 = 11/12
2) 4 2/15 + 3 5/6 = 62/15 + 23/6 = (62*2 + 23*5)/30 = (124 + 115)/30 = 239/30 = 7 29/30
3) 7 5/12 - ( 1 5/8 + 2 1/24 ) =
1) 1 5/8 + 2 1/24 = 13/8 + 49/24 = (13*3 + 49*1)/24 = (39 + 49)/24 = 88/24 = 11/3 = 3 2/3
2) 7 5/12 - 3 2/3 = 89/12 - 11/3 = (89*1 - 11*4)/12 = (89 - 44)/12 = 45/12 = 15/4 = 3 3/4