Question

If $a^2+b^2=41$ and $ab=4$, then find $a+b$.

• A. 6
• B. 5
• C. 7
• D. 8

Answer 1

The correct option is C 7

Formula ${(a+b)}^2=a^2+b^2+2ab$
Given, $a^2+b^2=41$ and $ab=4$
So, ${(a+b)}^2=a^2+b^2+2ab=41+2\times 4=41+8=49$

$=>a+b=\sqrt{49}=7$