Question

6. Find x-y, if x-y=5 and xy=14.​

Answer 1

ANSWER :

x+y=9

On squaring both sides ,

x

2

+y

2

+2xy=81

Putting value of xy = 14

x

2

+y

2

+28=81

x

2

+y

2

=81−28=53............(i)

(x−y)

2

=x

2

+y

2

−2xy

Putting xy = 14 and (i)

(x−y)

2

=53−2(14)=53−28

(x−y)

2

=25

⇒x−y=±

25

=±5