Other items mentioned in the Bible that start with Y include yarn (1 Kings 10:28), year (Psalms 54:17), and yoke[?] (Judges 29:10).
... getting <math>x^2+\frac{b}{a}x+\frac{b^2}{4a^2}=-\frac{c}{a}+\frac{b^2}{4a^2}.</math> The left side is now a perfect square; it is the square of (x + ...