$(5pts)$ Consider the following differential equation where $yis$ dependent variable,

$x^{2}dy-(y^2+2x^2)dx=0$

Which $of$ the following statement$(s)i\frac{s}{a}re$ CORRECT for the given differential equation,

I. It's a Separable equation.

$II.$ The solution $of$ the equation can $be$ found $by$ substitution $y=xu$

III. It's $an$ exact differential equation.

$IV.$ It's a Bernoulli's equation and $it$ can $be$ solved $by$ substitution $y^2=u$