Ответ:

  1. (9 · 16)/(8 · 27) = (9/27) · (16/8) = (1/3) · 2 = 2/3.

  2. (8 · 28)/(35 · 12) = (8/12) · (28/35) = (2/3) · (4/5) = 8/15.

Ответ: 2/3; 8/15.