" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
= p^2 + 2pq + q^2 + 4p^2 - 8pq + q^2 - 4p^2 - 12pq + 9q^2
= p^2 - 18pq + 11q^2