a) $$(3\sqrt{2})^2 = 9 \cdot 2 = 18$$
б) $$\sqrt{3} \cdot \sqrt{3} = 3$$
в) $$\sqrt{1+2(\sqrt{11})^2} = \sqrt{1 + 2 \cdot 11} = \sqrt{1 + 22} = \sqrt{23}$$
Ответ: a) 18; б) 3; в) $$\sqrt{23}$$