Question

Using suitable identity find the value of the following,
If (x-y) = 7 and xy = 9.Evaluate x2 + y2​

Answer 1

Answer:

67

Explanation:

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