Помогите пожалуйста с номером 1285

1) 4-1:(3-1:(2-1/2))= 4-1:(3-1:(1цел.1/2-1/2))=4-1:(3-1: 1цел.1/2)= 4-1:(3-1:3/2)= 4-1:(3-1*2/3)=4-1:(3-2/3)=4-1:(2цел 3/3-2/3)=4-1:2цел1/3= 4-1: 7/3=4-1*3/7=4-3/7=3цел7/7-3/7=3цел.4/72) 7-1:(5-1:(1-1/2))=7-1:(5-1:(2/2-1/2))=7-1:(5-1:1/2)=7-1:(5-1*2/1)=7-1:(5-2)=7-1:3=7-1/3= 6 цел.3/3-1/3=6цел.2/3,3) 6-2:(5-2:(4-2/3))= 6-2:(5-2:(3цел.3/3-2/3))=6-2:(5-2:3цел.1/3))=6-2:(5-2:10/3)=6-2:(5-2*3/10)=6-2:(5-3/5)=6-2:(4цел5/5-3/5)=6-2:4цел 2/5=6-2:22/5= 6-2*5/22= 6-5/11=5цел 11/11-5/11=5цел 6/114)3/4+7:(6-3:(5+8:(4-4/5))= 3/4+7:(6-3:(5+8:(3цел 5/5-4/5))=                         3/4+7:(6-3:(5+8:3цел 1/5))=3/4+7:(6-3:(5+8:16/5))=3/4+7:(6-3:(5+8*5/16))=3/4+7:(6-3(5+5/2))=3/4+7:(6-3:7(5+2цел 1/2))=               3/4+7:(6-3:7 цел 1/2)=3/4+7:(6-3:15/2)=3/4+7:(6-3*2/15)=3/4+7:(6-2/5)=              3/4+7:(5цел 5/5-2/5)=3/4+7:5цел.3/5= 3/4+7:28/5=3/4+7*5/28= 3/4+5/4=8/4=2/-это дробь *-это умножить  вроде-бы так