6a-1+4a-7+(-2a-2)= 6a-1+4a-7 -2a-2 =8а-10
16a-8+16a-8+8-16a= 16a-8
6a-1+4a-7+(-2a-2)=6a-1+4a-7-2a-2=8a-10 16a-8+16a-8+8-16a=16a-8
6a-1+4a-7+(-2a-2)= 6a-1+4a-7 -2a-2 =8а-10
16a-8+16a-8+8-16a= 16a-8
6a-1+4a-7+(-2a-2)=6a-1+4a-7-2a-2=8a-10 16a-8+16a-8+8-16a=16a-8