Respuesta :

the answer is 15 because hypotenuse equals a^2 + B^2 = √answer
a^2 + b^2 = c^2


With this, we can tell that

9*9 + 12*12 = X^2


81 +144 = X^2

225 = X^2

(take the square root of 225)

15 = X

therefore, option B is your answer :)