Solve the inequality LaTeX:  \displaystyle \frac{7}{x^{2} - 25}<\frac{8}{x^{2} - 4 x - 5}

Getting zero on one side and factoring gives LaTeX:  \displaystyle \frac{7}{\left(x - 5\right) \left(x + 5\right)} - \frac{8}{\left(x - 5\right) \left(x + 1\right)}< 0 . This gives the least common denominator as LaTeX:  \displaystyle \left(x - 5\right) \left(x + 1\right) \left(x + 5\right) . Building each fraction to get the common denominator gives LaTeX:  \displaystyle \frac{7 x + 7 - (8 x + 40)}{\left(x - 5\right) \left(x + 1\right) \left(x + 5\right)} < 0 . Simplifying gives LaTeX:  \displaystyle \frac{- x - 33}{\left(x - 5\right) \left(x + 1\right) \left(x + 5\right)}<0 . The inequality can change signs at the zeros of the numerator, LaTeX:  \displaystyle \left\{-33\right\} , or the zeros of the denominator LaTeX:  \displaystyle \left\{-5, -1, 5\right\} . Making a sign chart gives: This gives the solution LaTeX:  \displaystyle \left(-\infty, -33\right) \cup \left(-5, -1\right) \cup \left(5, \infty\right)