Solve the inequality LaTeX:  \displaystyle \frac{9}{x^{2} - 25}<\frac{5}{x^{2} + 8 x + 15}

Getting zero on one side and factoring gives LaTeX:  \displaystyle - \frac{5}{\left(x + 3\right) \left(x + 5\right)} + \frac{9}{\left(x - 5\right) \left(x + 5\right)}< 0 . This gives the least common denominator as LaTeX:  \displaystyle \left(x - 5\right) \left(x + 3\right) \left(x + 5\right) . Building each fraction to get the common denominator gives LaTeX:  \displaystyle \frac{9 x + 27 - (5 x - 25)}{\left(x - 5\right) \left(x + 3\right) \left(x + 5\right)} < 0 . Simplifying gives LaTeX:  \displaystyle \frac{4 x + 52}{\left(x - 5\right) \left(x + 3\right) \left(x + 5\right)}<0 . The inequality can change signs at the zeros of the numerator, LaTeX:  \displaystyle \left\{-13\right\} , or the zeros of the denominator LaTeX:  \displaystyle \left\{-5, -3, 5\right\} . Making a sign chart gives: This gives the solution LaTeX:  \displaystyle \left(-13, -5\right) \cup \left(-3, 5\right)