Question

(x^2-yx^2)dy+(y^2+xy^2)dx=0

Answer 1

$d((x {}^{2} - yx ^{2} ) \times c + (y ^{2} + xy^{2} )x) = 0$
$d(cx^{2} - cx^{2} y + xy^{2} + x^{2} y^{2} ) = 0$
$dx(cx - cxy + y^{2} + xy^{2} ) = 0$