Verified answer

8/15 · 1 3/8 : (2/5 + 7/10) · (-1 1/2) = -1

1) 2/5 + 7/10 = 4/10 + 7/10 = 11/10

2) 8/15 · 1 3/8 = 8/15 · 11/8 = 11/15

3) 11/15 : 11/10 = 11/15 · 10/11 = 10/15 = 2/3

4) 2/3 · (-1 1/2) = 2/3 · (-3/2) = -1

Ответ: (-1).