Question

If x^2 + y^2 = 14 and xy = 2 1/2, find the value of x-y ​

Answer 1

Answer:

1. a² + b² = (a - b)² + 2ab

• x² + y² = (x - y)² + 2xy

so,

$\sf{14={(x - y)}^{2}+\cancel2(\dfrac{1}{\cancel2})}$

$\sf14-1={(x - y)}^{2}$

$\sf13 ={(x - y)}^{2}$

$\sf\sqrt{13}=(x - y)$

$\sf{x - y = 3.59}$

$\sf{x - y =3\dfrac{59}{100} }$

(this answer is a round of number)