Respuesta :

[tex] \frac{9}{16} x^2 + xy + \frac{4}{9} y^2 = (\frac{3}{4} x)^{2} + xy + (\frac{2}{3}y)^{2} = (\frac{3}{4} x)^{2} + 2* \frac{3}{4} x * \frac{2}{3}y + (\frac{2}{3}y)^{2} [/tex] [tex]= ( \frac{3}{4}x + \frac{2}{3} y)^{2} [/tex]