1) -10 2/7 : 1 13/35=- 72/7 : 48/35= - 72/7 * 35/48= -3/1 *5/2 = - 15/2
2) 3 9/11 : 1 1/55=42/11 : 56/55=42/11 * 55/56=3/1 * 5/4=15/4
3) -15/2 + 15/4= - 30/4+15/4=-15/4= -3 3/4