1965 - In Selma, Alabama, State troopers and local law enforcement forcefully brake-up a group of 600 civil rights marchers. The event was televised and was dubbed "Bloody Sunday."
... to the expression to the left of "=", that will make it a perfect square trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), ...