Tend to Your Business

Tend To Your Business is a side quest in Fallout: New Vegas.

Detailed walkthrough
After Elder McNamara is ousted and Head Paladin Hardin becomes the new Elder, you are given the opportunity to join the Brotherhood of Steel through a heroic act. Hardin already has a task in mind; to wipe out the Van Graffs as a show of loyalty to the Brotherhood.

Conclusion
After eliminating the inhabitants of the Silver Rush, return to the Hidden Valley Bunker. Once there, inform Hardin that you have completed his task, and he will reward you with full membership into the Brotherhood of Steel, rewarding the player with a suit of T-45d power armor and a T-45d power helmet (a formal ceremony would apparently be inappropriate). In addition, the player receives the Power Armor Training perk, if they do not have it yet.