Question

Вычислите: а)1/4+4/7+9/28 б)1/5+3/10+7/20 в)3/20+7/30+2/40 г)17/20+23/30+11/60 д) 3/20+7/30+9/59 е) 7/40+11/70+13/30

Answer 1

а) 1/4 + 4/7 + 9/28 = 7/28 + 16/28 + 9/28 = 32/28 = 8/7 = 1  1/7

б) 1/5 + 3/10 + 7/20 = 4/20 + 6/20 + 7/20 = 17/20

в) 3/20 + 7/30 + 2/40 = 18/120 + 28/120 + 6/120 = 52/120 = 13/30

г) 17/20 + 23/30 + 11/60 = 51/60 + 46/60 + 11/60 = 108/60 = 9/5 = 1  4/5

д) 3/20 + 7/30 + 9/59 = 531/3540 + 826/3540 + 540/3540 = 1897/3540 - здесь, видимо, ошибка в записи?

е) 7/40 + 11/70 + 13/30 = 147/840 + 132/840 + 364/840 = 426/840 = 643/840