Question 83563
The ^ symbol is the exponent symbol. So when it says x^2 it means x to the 2nd power like this

{{{x^2}}}

Since we have a triangle with an unknown hypotenuse, we can solve for the hypotenuse using Pythagoreans theorem

Pythagoreans theorem:
{{{a^2+b^2=c^2}}}


{{{5^2+12^2=c^2}}} Let a=5,b=12, and lets solve for c


{{{25+144=c^2}}} Square each term


{{{169=c^2}}} Add


{{{sqrt(169)=sqrt(c^2)}}} take the square root of both sides


So our answer is 


{{{c=13}}}