" if "(a)/(b)+(b)/(a)=-1," then "(a^(3)-b^(3))=?

If (a)/(b)+(b)/(a)=-1(a,b!=0) the value of a^(3)-b^(3) is:

If the points ((a^(3))/(a-1),(a^(2)-3)/(a-1))((b^(3))/(b-1),(b^(2)-3)/(b-1)),((c^(3))/(c-1),(c^(2)-3)/(c-1)) are a!=1,b!=1,c!=1, then find the value of abc-(ab+bc+ca)+3(a+b+c)

If the points ((a^(3))/(a-1),(a^(2)-3)/(a-1)),((b^(3))/(b-1),(b^(3)-3)/(b-1)) and ((c^(3))/(c-1),(c^(3)-3)/(c-1)) where a,b,c are different from 1 lie on the line lx+my+n=0a+b+c=(m)/(l)ab+bc+ca+(n)/(l)=0abc=((3m+n))/(l)abc-(bc+ca+ab)+3(a+b+c)=0