4n(n-1)-3n(2n+4)+2n(n-2) и решить !

1)4n-(n-1)-3n(2n+4)+2n(n-2)
4nn+4n*-1-3n(2n+4)+2n(n-2)
4n^2+4n*-1-3n(2n+4)+2n(n-2)
4n^2-4n-3n(2n+4)+2n(n-2)
4n^2-4n+(-3n(2n)-3n*4)+2n(n-2)
4n^2-4n+(-3(2n^2)-12n)+2n(n-2)
4n^2-4n+(-6n^2-12n)+2n(n-2)
4n^2-4n+(-6n^2-12n)+(2n^2+2n*-2)
4n^2-4n+(-6n^2-12n)+(2n^2-4n)
4n^2-4n-6n^2-12n+2n^2-4n
-2n^2-4n-12n+2n^2-4n
-4n-12n+0-4n
-16n+0-4n
-16n-4n
-20n