-20 2/7 : 1 13/35 + 3 9/11: 1 1/55

Question

-20 2/7 : 1 13/35 + 3 9/11: 1 1/55

Answer 1

   -20 2/7 : 1 13/35 + 3 9/11 : 1 1/55 =
= -142/7 * 35/48 + 42/11 * 55/56 = -(121*5)/24 + (21*5)/28 =
= (21*5*6)/168 - (121*5*7)/168 = 630/168 - 4235/168 =
= - 3605/168 = - 21 77/168 = - 21 11/24