Question

(x square + xy ) dy = ( x square + y square) dx

Answer 1

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