1)4а-(5а-(а-3))=4а-5а-а-3=а-3
2) 4b-(5b-(b-7)=4b-5b-b-7=b-7
1) 4а-(5а-(а-3))= 4а-5а+(а-3)=4а-5а+а-3= 3
2) 4b-(5b-(b-7)= 4б-5б+(б-7)=4б-5б+б-7= 7
1)4а-(5а-(а-3))=4а-5а-а-3=а-3
2) 4b-(5b-(b-7)=4b-5b-b-7=b-7
1) 4а-(5а-(а-3))= 4а-5а+(а-3)=4а-5а+а-3= 3
2) 4b-(5b-(b-7)= 4б-5б+(б-7)=4б-5б+б-7= 7