Решаем по действиям:
1) 1, 1/12 + 1 5/8=13/12 + 13/8=104/96+156/96=260/96=2 68/96= 2 17/24
2)1. 1/12-1. 5/8 = 13/12 - 13/8=104/96-156/96=- 52/96= - 13/24
3)2 17/24 * (-1 11/13)= 65/24 *( -24/13)=-65/13=-5
4)- 13/24 * 1 7/26= - 13/24 * 33/26= -11/16
5) -5 - (-11/16)=-5 + 11/16= -4 5/16
Ответ: -4 5/16