Simplify : $( 1+\large\frac{1}{2}x +\frac{1}{\sqrt 2} x^2)$$+(5 -\large\frac{2}{3}x $$+\sqrt 2 x^2) -(4 - \large\frac{1}{3} x -$$ 2 \sqrt 2 x^2)$

Question

$\begin{array}{1 1} \sqrt 7 x^2+\frac{1}{6}x +2 \\ \frac{7}{\sqrt 2} x^2+\frac{1}{6}x +2 \\ \frac{7}{\sqrt 2} x^2+\frac{1}{6}x \\ \sqrt 7 x^2+2 \end{array} $