Simplify using the horizontal method (2n^2+5n+5)(2n-4)

(2n^2 + 5n + 5)(2n - 4)

= 2n^2(2n) + 5n(2n) + 5(2n) - 4(2n^2) - 4(5)
= 4n^3 + 10n^2 + 10n - 8n^2 - 20
= 4n^3 + 2n^2 + 10n - 20