User:Piphi/AoPS Wiki/Template:Weeklyproblem

Problem of the Week

2012 AMC 12A, Problem 21

Let $a$, $b$, and $c$ be positive integers with $a\ge$ $b\ge$ $c$ such that $a^2-b^2-c^2+ab=2011$ and $a^2+3b^2+3c^2-3ab-2ac-2bc=-1997$. What is $a$?