Answer
$${\text{ellipse}}$$
Work Step by Step
$$\eqalign{
& {y^2} + 9{x^2} = 9 \cr
& {\text{Divide both sides by 9}} \cr
& \frac{{{y^2}}}{9} + \frac{{9{x^2}}}{9} = \frac{9}{9} \cr
& \frac{{{y^2}}}{9} + {x^2} = 1 \cr
& {\text{The equation is written in the form }}\frac{{{x^2}}}{{{b^2}}} + \frac{{{y^2}}}{{{a^2}}} = 1\,\,\,\,\left( {{\text{Where }}a > b} \right) \cr
& {\text{Therefore,}} \cr
& {\text{The graph of the equation is an ellipse}} \cr} $$
