The result of $\displaystyle \frac{7x-\frac92\sqrt[6]{y^5}}{\left(x^{\frac56}-6y^{-\frac13}\right)x^{-2}}$ for x = 4 and y = 27 is ....

a. $\displaystyle \left(1+2\sqrt2\right)9\sqrt2$

b. $\displaystyle \left(1+2\sqrt2\right)9\sqrt3$

c. $\displaystyle \left(1+2\sqrt2\right)18\sqrt3$

d. $\displaystyle \left(1+2\sqrt2\right)27\sqrt2$

e. $\displaystyle \left(1+2\sqrt2\right)27\sqrt3$

I got stuck at $\displaystyle \frac{56-3^2\left(3^{\frac52}\right)}{2^-{\frac43}-2^{-2}}$ and don't know how to continue to reach one of the options. By the way, don't you think that 7 is suspicious?