I don’t understand graphing.

Given abcd ac=38 and ae=3x+4 find the value of x

This is about circle theorems. someone asap : (

Ms. ortiz sells tomatoes wholesale. the function p(x)=-80x^2+320x-10, graphed below, indicates how much profit she makes on a load of tomatoes if she makes on a load of tomatoes if she sells them for 4-x dollars per kilogram. what should ms. ortiz charge per kilogram of tomatoes to make on a load of tomatoes?