This is a complicated issue. If the partnership has made a sec 754 election than you may have to adjust the inside basis to outside basis. Attached is a link to explain what it really means.
However, if the partnership has not made this election(which is also good in this case) - Your inside basis in the partnership will be your original basis plus 50% of the outgoing partner;s basis and same will apply to the other partner. Hence, you will make the entry as you mentioned.
Note that if you make this deal outside of the partnership - such as you both are buying out the partner - no gain or loss will be currently recognized in the partnership unless there is a section 754 election in place. Since the assets in the partnership have depreciated in value, it is not a good idea to make such election too.
You may want to (and I would also suggest you to) engage a professional to help you evaluate the tax consequences with detailed information on the partnership taxes, assets etc.
Let me know if you have any question.
Please note: This advice is provided with the understanding that all the relevant facts have been provided by you. Any change in facts might affect the advice given and hence may not be relied on in such cases. Nothing contained in this reply was intended or written to be used, can be used by any taxpayer, or may be relied upon or used by any taxpayer for the purposes of avoiding penalties that may be imposed on the taxpayer under the Internal Revenue Code of 1986, as amended.