Answer:
x = 17
Explanation:
This is a right triangle so we can use the Pythagorean theorem
a^2 + b^2 = c^2 where a and b are the legs and c is the hypotenuse
15^2 + x^2 = (sqrt(514))^2
225 + x^2 = 514
Subtract 225 from each side
225-225 + x^2 = 514-225
x^2 =289
Take the square root of each side
sqrt(x^2) = sqrt(289)
x = 17