wow, mathematic discussion group here.
I oso hope can help others in maths.

instead of posting questions here y dun ask classmates or frens?
the explanation in the reference or text book is clear enuf jor.

For the chemistry subject, why don't you go try do the pas year questions(with answers and explanation provided)?
Last time i write the answers and explanations on each questions so is easier to refer back when revision. Write on your own, what you have wrote may help you memorize it.