Question

SECTION B Fach questions carry 3 marks each)
6. If x - y = 7 and xy = 9, find the value of xy?)
7. Factorise: x? - 11x - 42​

Answer 1

Answer:

6).

Given, x−y=7 and xy=9

x−y=7

Squaring both sides, we get,

(x−y)

2

=7

2

=>x

2

+y

2

−2xy=49

=>x

2

+y

2

−2(9)=49

=>x

2

+y

2

=49+18

=>x

2

+y

2

=67