i need to do without using excel can you explain step by step?

0-2. (IRR calculation) Determine the IRR on the following projects: a. An initial outlay of $12,000 resulting in a single free cash flow of $17,231 after 7 years b. An initial outlay of $12,000 resulting in a single free cash flow of $48,956 after 9 years c. An initial outlay of $12,000 resulting in a single free cash flow of $114,847 after 21 years d. An initial outlay of $12,000 resulting in a single free cash flow of $13,874 after 4 years