Решительно дроби 5/6+1/8= 13/15-1/3= 8/21-2/7= - вопрос №583562056181315138212712132719 от Veratandashvili 15.05.2021 21:49

Question

Математика: Решительно дроби 5/6+1/8= 13/15-1/3= 8/21-2/7= 1/2+1/3= 2/7-1/9=

Veratandashvili · Answer

5/6 + 1/8 = (5 × 4 + 1 × 3)/24 = 20/24 + 3/24 = 23/24
13/15 - 1/3= (13 × 1 - 1 × 5)/15 = 13/15 - 5/15 = 8/15
8/21 - 2/7 = (8 × 1 - 2 × 3)/21 = 8/21 - 6/21 = 2/21
1/2 + 1/3 =(1 × 3 + 1 × 2)/6 = 3/6 + 2/6 = 5/6
2/7 - 1/9 =(2 × 9 - 1 × 7)/63 = 18/63 - 7/63 = 11/63