Ответ :


[tex]9 \cdot81 \div {3}^{ \frac{1}{2} } = {3}^{2} \times {3}^{4} \div {3}^{ \frac{1}{2} } = \\ = {3}^{2 + 4 - \frac{1}{2} } = {3}^{5 \frac{1}{2} } = {3}^{5} \sqrt{3} = \\ = 243 \sqrt{3} [/tex]