with logic:

5+6 = 341
11 = 341
341/11 = 31

6+7 = 559
13 = 559
559/13 = 43

43 - 31 = + 12

7+8 = 855
15 = 855
855/15 = 57

57 - 43 = + 14

8 + 9 = ?
17 = ?
57 + 16 = 73
73 * 17 = 1241

9 + 10 = ?
19 = ?
73 + 18 = 91
91 * 19 = 1729

9 + 10 = 1729