[math]x{\small_1}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/máth]

x{\small_1}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}

That's not a logarithmic equation. That's a formula to solve quadratic equations.

Say I have a quadratic equation:

ax^2 + bx + c = 0

To solve this, you apply the formula, x{\small_1}=\frac{-b\pm\sqrt{b^2-4ac}}{2a} to get the value of x.