Solve for $\displaystyle {x}$ :

$\displaystyle \frac{{7}}{{{x}^{{2}}-{7}{x}+{12}}}+\frac{{4}}{{{x}^{{2}}-{9}}}=\frac{{6}}{{{12}-{3}{x}}}$
$\displaystyle {x}=$  Preview Question 6 Part 1 of 2
	(type: "x=? is not applicable" if one of the solutions is not applicable)