Consider the B+ tree index shown in the figure below. Each intermediate node can hold up to five pointers and four key values. Each leaf can hold up to four records, and leaf nodes are doubly linked as usual, although these links are not shown in the figure. Answer the following questions. Please show every step of the insertion and explain the process.

1. Insert a record with search key 109 into the tree.

2. Delete the record with search key 81 from the original tree.

301 31 Ll L2 30 80 Il 35 42 50 65 90| 98 12 68* 69* 70* 79 98 99 100 10 L8 511 521 56 60 94 95 96 97 L7 si 82 42- 43 L6