Вычислите
(1-3/13+2-2/13)+3-7/13=
5-7/18+(4-11/18+2-10/18)=
5-5/17+(6-16/17+13-8/17)=
11-16/23+(4-14/23+7-13/23)=

(1-3/13+2-2/13)+3-7/13= 2*8/13+2*6/13=5*1/135-7/18+(4-11/18+2-10/18)= 4*11/18+4*15/18=9*8/18=9*4/95-5/17+(6-16/17+13-8/17)= 4*12/17+17*10/17=22*5/1711-16/23+(4-14/23+7-13/23)= 10*7/23+9*19/23=20*3/23