Question

If $a^2+b^2=29$ and $ab=10$, then find $a+b$.

• A. 19
• B. 20
• C. 10
• D. 7

Answer 1

The correct option is D 7

Formula ${(a+b)}^2=a^2+b^2+2ab$
Given, $a^2+b^2=29$ and $ab=10$
So, ${(a+b)}^2=a^2+b^2+2ab=29+2\times 10=29+20=49$

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