Distance simple math problem, 10 points best answer

Im learning Midpoint and distance and all this crap. Can you tell me if the distance is right.
(-7,-8) (8,-6)
is the answer 229? if im wrong can you please tell me how to do it
This is how i worked out this problem
(8- -7) squared + (-6- -8) squared
225+4=229

You need to square root it.

√(229)

Formula is:
D = √((x1-x2)^2 + (y1-y2)^2)