Answer Happy

Hello, can you please help me with this question? its onequestion containing a couple parts. please make sure to answer allthe parts for a up vote. also make sure to show all steps clearlyand circle the final answers. thank you.
1. Find each limit, if it exists. You can use algebra methods only to simplify fraction. a) u→−3lim​u2+2u−3u2−9​ b). x→∞lim​5x2−4x+36+x−3x2​ c) h→0lim​h(3+h)2−9​