PLEASE HELP!!.it's easy I just don't know how to do the last two

In which form is the following function written? y = - 2(x – 3)(x + 5)

In the figure below, ∠dec ≅ ∠dce, ∠b ≅ ∠f, and segment df is congruent to segment bd. point c is the point of intersection between segment ag and segment bd, while point e is the point of intersection between segment ag and segment df. the figure shows a polygon comprised of three triangles, abc, dec, and gfe. prove δabc ≅ δgfe.

If you could answer these your a life saver