Question

1. (n^2-1)*(n^4+n^2+1)-(n^2-1)^3

Answer 1

$\(n^2-1)*(n^4+n^2+1)-(n^2-1)^3= \. \(n^2-1)[(n^4+n^2+1)-(n^2-1)^2]= \. \(n^2-1)(n^4+n^2+1-n^4+2n^2-1))= \. \3n^2(n^2-1)=3n^4-3n^2$