If a+b=13 and a-b= 3,then value of a2+b2 =?

If a+b=13 and a-b= 3,then value of a²+b² =?

A 69

B 79

C 89

D 91

Solution

Correct Answer: Option C

Here, a+b=13 and a-b= 3

So, a2+b2={(a+b)2+(a-b)2}/2

= {(13)2+(3)2}/2

=(169+9)/2

=178/2=89