## Algebra: A Combined Approach (4th Edition)

x = 3$y^{2}$ + 6y + 7 x = 3[ $y^{2}$ + 2y + $\frac{7}{3}$ ] x = 3[ $(y+1)^{2}$ - 1 + $\frac{7}{3}$ ] x = 3[ $(y+1)^{2}$ + $\frac{4}{3}$ ] x = 3$(y+1)^{2}$ + 4 Thus vertex = (4, -1)