Question

If x² + y2 = 9 and (x - y)2 = 3, what is the
value of xy?
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Answer 1

Given, x2+y2 =9

and, (x-y)^2 =3

Now, x2+y2 = (x-y)2 +2xy

or, 9=3 +2xy

or, 2xy =6

or xy = 6/2 =3

Answer 2

Answer:

3

Step-by-step explanation:

x2+y2=9. (given) (1)

(x-y)2=3

x2+y2-2xy =3

9-2xy =3. (from 1)

-2xy=3-9

-2xy= -6

2xy=6

xy=3