Question

If \(a^2+b^2=41\) and \(ab=20\), then the value of \(a+b\) is

• A. 7
• B. 9
• C. 11
• D. 8

Hint:

Expand (a+b)^2 = a^2 + b^2 + 2ab and substitute the given values.

Answer 1

The Correct Option is B

Step 1: Guess integer factors of 20.
Pairs with product $20$: $(4,5)$ gives $16+25=41$.
Step 2: Add them.
$a+b=4+5=9$.
\[\boxed{9}\]