Verified answer

Объяснение:

1.

а) 1/7 * 14/15 = 1/1 * 2/15 = 2/15

б) 2/3 : 4 = 2/3 * 1/4 = 1/3 * 1/2 = 1/6

в)

1) 54,9 : 1,83 = 30

2) 1,2 * 3 = 3,6

3) 30 - 3,6 = 26,4

г)

1) 2 1/3 + 5 3/7 = 2 7/21 + 5 9/21 = 7 16/21

2) 7 16/21 * 2,1 = 7 16/21 * 2 1/10 = 163/21 * 21/10 = 163/1 * 1/10 = 163/10 = 16 3/10 или 16,3