Evaluate 20 + 12 + 3 729 - 4 5 - 3 - 81

Answer: Option C

$$\begin{array}{rl}& \sqrt{20}+\sqrt{12}+\text{root}3\text{of}729-\frac{4}{\sqrt{5}-\sqrt{3}}-\sqrt{81}\\ & \Rightarrow 2\sqrt{5}+2\sqrt{3}+9-\left(\frac{4}{\sqrt{5}-\sqrt{3}}\times \frac{\sqrt{5}+\sqrt{3}}{\sqrt{5}+\sqrt{3}}\right)-9\\ & \Rightarrow 2\sqrt{5}+2\sqrt{3}+9-\left(\frac{4\left(\sqrt{5}+\sqrt{3}\right)}{2}\right)-9\\ & \Rightarrow 2\sqrt{5}+2\sqrt{3}+9-2\sqrt{5}-2\sqrt{3}-9\\ & \Rightarrow 0\end{array}$$