A prebendal stall is a seat, usually in the back row of the choir stalls, where a prebendary[?] sits. It was a place of honor for dignitaries who where members of clergy on staff at a cathedral or collegiate church.
The title Prebendary was given to a person who holds a prebend[?] (also known as prebendal lands). These leaders were given an endowment[?] of land, or a pension of money.
... 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), so we add the ...