Question

Si x - y=4
xy = 2,
calcula x2 +y2

Con resolución porfavor

Answer 1

Respuesta:

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

$x-y=4\\x^{2} +y^{2}=?$

$xy=2$

Remplazamos:

$(4)^{2} =x^{2} +y^{2}-2(2)$

$16=x^{2} + y^{2}-4$

$x^{2}+y^{2}=20$