Question

Упростите выражение:
$frac{3x+y}{x^{2}+xy } - frac{x+3y}{ y^{2} +xy}$

Answer 1

$frac{3x+y}{x(x+y)}- frac{x+3y}{y(y+x)}= frac{y(3x+y)-x(x+3y)}{xy(x+y)}= frac{3xy+ y^{2}- x^{2} -3xy }{xy(x+y)}= \ frac{(y-x)(x+y)}{xy(x+y)}= frac{(y-x)}{xy}$