Question

If x+y = - 4 and xy=2, then
the value of x² + y ² is ..................​

Answer 1

Answer:

X+Y=-4

(X+Y)^2=4^2

X^2 + Y ^2+ 2xy = 16

x^2+y^2=12

Answer 2

Given:

$\sf{x+y = - 4}$

$\sf{xy=2}$

To find:

$\sf{x^2 + y^2}$

Identity Used:

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

Solution:

Substituting the given values in the above identity, we get,

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

$\sf{\implies 16=x^2+y^2+4}$

$\sf\boxed{\therefore x^2+y^2=12}$