Find the vertex of the graph of the equation $x - y^2 + 8y = 13 + 2y + y^2 - 7y - 14$.
We can rewrite the equation as x−y2+8y=13+2y+y2−7y−14 2y2+9y+x=0 2(y2+92y+x2)=0 0=(y+94)2+x−8116This is a parabola, opening upwards, with vertex at (1681,4−9).