Вычислите 1 целая 2/3 -5/14+(1целая 3/4-1/12)-4/21 - вопрос №7355215123514134112421 от raivon2005new 25.08.2020 05:34

Question

Математика: Вычислите 1 целая 2/3 -5/14+(1целая 3/4-1/12)-4/21

raivon2005new · Answer

1) 1 3/4 - 1/12 = 7/4 - 1/12 = (7 × 3 - 1 × 1)/12 = 21/12 - 1/12 = 20/12 = 5/3 = 1 2/3
2) 1 2/3 - 5/14 = 5/3 - 5/14 =(5 × 14 - 5 × 3)/42 = 70/42 - 15/42 = 55/42 = 1 13/42
3) 13/42 + 1 2/3 = 55/42 + 5/3 = (55 × 1 + 5 × 14)/42 = 55/42 + 70/42 = 125/42 = 2 41/42
4) 2 41/42 - 4/21 = 125/42 - 4/21 = (125 × 1 - 4 × 2)/42 = 125/42 - 8/42 = 117/42 = 39/14 = 2 11/14
ответ: 2 11/14