Question

X^2+Y^2=7,XY=3,then X-Y=??? ​

Answer 1

`\huge\boxed{\sf x - y = \pm 1}`

Explanation:

Given that:

x² + y² = 7

xy = 3

We know that:

(x - y)² = x² + y² - 2xy

Put the above givens in the formula.

(x - y)² = 7 - 2(3)

(x - y)² = 7 - 6

(x - y)² = 1

Take sqrt on both sides

x - y = ±1

`\rule[225]{225}{2}`