Please help with these. I will give you brainlist

Write as a product: ac^2–ad+c^3–cd–bc^2+bd

Ineed asap. 35 points. in order for two polygons to be similar, two conditions must be met. first, all pairs of corresponding sides must be in proportion. second, all corresponding angles must be congruent. prove that angle congruence is not enough, by itself, to establish that two polygons are similar. do this by describing or drawing two polygons that are not similar but whose corresponding angles are all congruent.

Hdtv screens usually have a width-to -height ratio of 16: 9. which screen dimensions are in the same proportion?