Answer
$${\text{hyperbola}}$$
Work Step by Step
$$\eqalign{
& {x^2} = 25 + {y^2} \cr
& {\text{Subtract }}{y^2} \cr
& {x^2} - {y^2} = 25 \cr
& {\text{Divide by 25}} \cr
& \frac{{{x^2}}}{{25}} - \frac{{{y^2}}}{{25}} = 1 \cr
& {\text{The equation is in the form }}\frac{{{x^2}}}{{{a^2}}} - \frac{{{y^2}}}{{{b^2}}} = 1 \cr
& {\text{Therefore, the equation represents a hyperbola}} \cr
& {\text{Graph}} \cr} $$