(r^2 - 2s) (2r^2 + s) Simplify?

Question

(r^2 - 2s) (2r^2 + s) Simplify.

( ^ is the exponet)

Answer 1

just mulitply through
2r^4 + r^2s-4r^2s+2s^2 Collect Like terms next
2r^4 - 3r^2s + 2s^2 Final answer

Answer 2

= 2r^(4) + r² s - 4 r² s - 2 s²
= 2 r^(4) - 3 r² s - 2 s²

Answer 3

2r^4-3r^2s-2s^2