latex code

Here’s the LaTeX code for that expression:

latex
$x_1 = \frac{k + \sqrt{k^2 + 8}}{2}, \quad x_2 = \frac{k - \sqrt{k^2 + 8}}{2}$

Or in display mode:

latex
$$
x_1 = \frac{k + \sqrt{k^2 + 8}}{2}, \quad
x_2 = \frac{k - \sqrt{k^2 + 8}}{2}
$$