Question 759258
(-6rs+s^2)^2
(-6rs+s^2)(-6rs+s^2)
apply FOIL:
(-6rs)(-6rs) + (-6rs)(s^2) + (s^2)(-6rs) + (s^2)(s^2)
(36r^2s^2) + (-6rs^3) + (-6rs^3) + (s^4)
36r^2s^2 - 6rs^3 - 6rs^3 + s^4
combine middle terms:
36r^2s^2 - 12rs^3 + s^4