What do you want to do with this? It doesn't factor nicely, so perhaps you want to find the values of x that make the expression equal zero. If so you could use the quadratic equation \(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\) or complete the square.
Set the expression equal to 0 and divide through by -12: \(x^2 + \frac{x}{12}-\frac{7}{12}=0\)
Add \((\frac{1}{2\times12})^2 \rightarrow \frac{1}{576}\) to both sides and add 7/12 to both sides:
\(x^2+\frac{x}{12}+\frac{1}{288}=\frac{1}{576}+\frac{7}{12}\)
The left hand side is now a perfect square and, since 7/12 = 376/576 we can write \((x+\frac{1}{24})^2=\frac{337}{576}\)
Take the square root of both sides: \(x=-\frac{1}{24}\pm\frac{\sqrt{337}}{24}\)
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