How would you do

_______
\/ 388
_____
6

I need it for a quadratic equation it's
________
-10 + or - \/ 388
______
6

____
the answer is -5+ or - \/ 97
___
3
how did they get that ?? any help?

√388 = √4 √97

= 2√97

so (-10 ± √388)/10
= (-10 ± 2√97)/6
= (-5 ±√97)/3 after dividing top and bottom by 2