I'm pretty sure I understand these but still having trouble with some...

So if someone could help me?

Find and equation of the line that contains a diameter of a circle x^2+y^2+2x-4y=4,

and which is parallel to the line 3x+5y=4.

I can get as far as factoring but I think I'm doing it wrong. Help please?

And I'm not sure if this has anything to do with the lesson but our teacher asked us to solve it.

Let w,x,y, and z be positive real numbers. Prove that

(w+x)(x+y)(y+z)(z+w)>16wxyz

Second one isn't as important but if someone could help me understand it, I would really appreciate it.