Hi, I have a question that asks: Write an equation of the tangent to each curve at the given point. $\displaystyle y = \sqrt{3x^3} $

I've been trying to do the question, but I end up with decimals in the equation for the tangent. The answer is supposed to be $\displaystyle 9x -2y - 9 = 0 $. Thanks in advance.

EDIT: Sorry about that, the given point is $\displaystyle P(3,9)$