(1 9/16*3 1/5+16 2/3-9:2 2/5):(17 7/12-6 1/3)=

Приведем смешанные дроби к виду обычных:

1) 1 9/16 = (1 * 16 + 9)/16 = 25/16;

2) 3 1/5 = (3 * 5 + 1)/5 = 16/5;

3) 16 2/3 = (16 * 3 + 2)/3 = (48 + 2)/3 = 50/3;

4) 2 2/5 = (2 * 5 + 2)/5 = 12/5;

5) 17 7/12 = (17 * 12 + 7)/12 = (204 + 7)/12 = 211/12;

6) 6 1/3 = (6 * 3 + 1)/3 = 19/3;

Запишем и решим выражение:

(25/16 * 16/5 + 50/3 - 9 : 12/5) : (211/12 - 19/3) = (25/5 + 50/3 - 9 *5/12) : (211/12 - 76/12) = (5 + 50/3 - 15/4) : 135/12 = (60/12 + 200/12 - 45/12) * 12/135 = 215/12 * 12/135 = 215/135 = 43/27.

Ответ: 43/27.