Question

6/2а-а2 - 3/а при а=-4

Answer 1

6:2•4-4•2-3•4= -8
Вот так??

Answer 2

6/(2а-а^2)-3/а=
6/а(2-а)-3/а=
[6-3(2-а)]/[а(2-а)]=
(6-6+3а)/[а(2-а)]=
3а/а(2-а)=
3/(2-а)=
3/(2-(-4))=
3/(2+4)=
3/6=
1/2=0.5