1) (1 3/28-25/42-5/14):2 2/13+11/13:1 7/26= 2) (2 1/12:2 1/2+(1 9/28-16/35)*2 6/11-11/30=

1) (1 3/28-25/42-5/14): 2 2/13+11/13:1 7/26= 1 -25/42-5/14=-25/42-15/42= -40/42= -20/21 1 3/28-20/21=31/28-20/21= 186/168-160/168=26/168= 13/84 13/84:2 2/13=13/84×28/13=1/3 11/13: 1 7/26=11/13×26/33=2/3 1/3+2/3=3/3=1 2) (2 1/12:2 1/2)+(1 9/28-16/35)*2 6/11-11/30= 2 1/12:2 1/2=25/12×2/5=5/6 1 9/28-16/35=37/28-16/35= 185/140-64/140=121/140 121/140×2 6/11= 121/140×28/11=11/5 5/6+11/5-11/30= 25/30+66/30-11/30=80/30=2 20/30= 2 2/3