Consider the RB tree below. Dotted lines refer to a red node. The last page shows the cases for RB deletion that you can consider.

(a) delete 17 from this tree

(b) delete 7 from the same tree (the original tree, before the deletion of 17 above)

8 4. 18 2 12 20 1 3 5 7 10 16 19 21 9 11 14 17 22 13 15