Divide and simplify:

$\displaystyle \frac{{{x}^{{2}}-{4}}}{{{x}^{{2}}+{5}{x}-{14}}}\div\frac{{{3}{x}}}{{{x}+{7}}}$

Enter the numerator and denominator separately in the boxes below. If the denominator is 1, enter the number 1. Do not leave either box blank. Answer: