Junior Cert Math Tutor

I need help understanding some of the problems in Algebra and how they are solved ?

Can you answer the following algebraic expression problem giving me explanations of the step by step solution Q: Multiply out and simplify 4x (5x+4) - 3 (x-2)

Help me solve this algebra problem Q: Factorize fully 9 - 25y²

Amie and Joe are asked to pick values for the following letters p, q and r so that the statement is true for all a ∈ ℝ aP X aq X ar = a12 Part A) Amie picked three values that were all the same, so p = q = r write down the values of p, q and r that Amie picked. Part B) Joe picked three values that were all different. Write down possible values of p, q, and r that Joe might have picked.

Can you provide me some details about how Junior Cycle Math solutions are marked/graded ?