Ответ:

Пошаговое объяснение:

1) 2/5 + x = 1 2/15

x = 1 2/15 - 2/5

x = 1 2/15 - 6/15

x = 17/15 - 6/15

x = 11/15

2) x - 2/5 - 0,3 = 2 1/4

x = 2 1/4 + 3/10 + 2/5

x = 7 1/4 + 3/10 + 2/5

x = 7 5/20 + 6/20 + 8/20

x = 7 19/20