Найдите сумму чисел 5 3/7 и 3 4/21:1)2 5/21;2)8 1/3;3)8 1/4;4)8 13/21

Ответ учителя по предмету Математика

5 3/7 + 3 4/21 /1 = 38/7 + 67/21 = 114/21 + 67/21 = 181/21 = 8 13/21

5 3/7 + 2 5/21 = 38/7 + 47/21 = 114/21 + 47/21 = 161/21 = 7 14/21 = 7 2/3

5 3/7 + 8 1/3 = 38/7 + 25/3 = 114/21 + 175/21 = 289/21 = 13 16/21

5 3/7 + 8 1/4 = 38/7 + 33/4 = 152/28 + 231/28 = 383/28 = 13 19/28

5 3/7 + 8 13/21 = 38/7 + 181/21 = 114/21 + 181/21 = 295/21 = 14 1/21