Question 1004302
Please see this lesson because it explains and tells you  what to do.

<a href="http://www.algebra.com/my/Completing-the-Square-to-Solve-General-Quadratic-Equation.lesson?content_action=show_dev">How to solve a quadratic equation, and you can simply use the general formula instead of Completing the Square</a>


Your second example equation,
{{{x=(-7+- sqrt(7^2-4*3*(-13)))/(2*3)}}}