Question

Can somebody help with these three questions plz

Answer 1

`\bf √(2)\left(3√(2)+√(18) \right)~~ \begin{cases} 18=2\cdot 3\cdot 3\\ \qquad 2\cdot 3^2 \end{cases}\implies √(2)\left(3√(2)+√(2\cdot 3^2) \right) \\\\\\ √(2)\left(3√(2)+3√(2) \right)\implies √(2)\left(6√(2) \right)\implies 6\left(√(2)\right)^2\implies 6\cdot 2\implies \stackrel{rational}{12}`