(i) (3xy + y2)dx + (x2 + xy)dy = 0
\(⇒ \frac{dy}{dx} = -\frac{3xy + y^2}{x^2 + xy}\) = f(x,y)
Replace x by λx and y by λy
F(λx, λy) = -\(\frac{3λ^2xy + λ^2y^2}{λ^2x^2 + λ^2xy}\)
\(\frac{λ^2(3xy + y^2)}{λ^2(x^2 + xy)}\) = λ0 F(x,y)
F(x,y) is a Homogenous DE of degree 2.