Si xy = 10 ; [tex] x ^ {2} [ / tex] = 7 hallar y si [tex] (x + y) ^ {2} [ / tex] = 40?

@Vamoahi

Veamos :

xy = 10

<img src="https://tex.z-dn.net/?f=%20x%5E%7B2%7D%20" /> = 7

Ahora si :

<img src="https://tex.z-dn.net/?f=%20%28x%2By%29%5E%7B2%7D%20" />

Usaremos a los productos notables

<img src="https://tex.z-dn.net/?f=%20x%5E%7B2%7D" /> + 2xy + <img src="https://tex.z-dn.net/?f=%20y%5E%7B2%7D%20" /> = 40

y eso se resume a :

7 + 2(10) + <img src="https://tex.z-dn.net/?f=%20y%5E%7B2%7D%20" /> = 40

<img src="https://tex.z-dn.net/?f=%20y%5E%7B2%7D%20" /> = 40 - 27

<img src="https://tex.z-dn.net/?f=%20y%5E%7B2%7D%20" /> = 13

y = <img src="https://tex.z-dn.net/?f=%20%5Csqrt%7B13%7D%20" />

Espero haberte ayudado

#Yuraotro.