Ok so, for a, the hint is to use add your own point! Think of a way to link y to x :) in this case, BE=y and is common for both the square and trapezium, so think of a way to find BE in terms of x.

For b, it should be simpler. You’ve likely learnt the formula for area of trapezium. If you haven’t, you can split the trapezium into triangles and rectangles to get its area. Just apply the formulas for areas and use the relation found in a to make everything in terms of x! In exam, even if you can’t do a, since a is a show question, don’t give up on b!

For c, just solve the quadratic eqn and reject an answer since you only want one final answer. When rejecting, sub the value in stuff to figure out if it’s realistic. Once you reach there, you should be fine