Question 311410
10= sqrt 8^2+x^2 
First, we should square both sides to get rid of the square root sign. It should end up like this:
10^2=8^2+x^2, and then solve the square roots:
100=64+x^2
Subtract 64 from both sides, so it ends up like this:
36=x^2
Then, find the square root of both sides. It should end up with this:
x=6.
I hope I helped!