Solve the inequality LaTeX: \displaystyle \frac{4}{x^{2} - 4}<\frac{4}{x^{2} - 3 x + 2}

Getting zero on one side and factoring gives LaTeX: \displaystyle \frac{4}{\left(x - 2\right) \left(x + 2\right)} - \frac{4}{\left(x - 2\right) \left(x - 1\right)}< 0 . This gives the least common denominator as LaTeX: \displaystyle \left(x - 2\right) \left(x - 1\right) \left(x + 2\right) . Building each fraction to get the common denominator gives LaTeX: \displaystyle \frac{4 x - 4 - (4 x + 8)}{\left(x - 2\right) \left(x - 1\right) \left(x + 2\right)} < 0 . Simplifying gives LaTeX: \displaystyle - \frac{12}{\left(x - 2\right) \left(x - 1\right) \left(x + 2\right)}<0 . The inequality can change signs at the zeros of the numerator, LaTeX: \displaystyle \emptyset , or the zeros of the denominator LaTeX: \displaystyle \left\{-2, 1, 2\right\} . Making a sign chart gives: This gives the solution LaTeX: \displaystyle \left(-2, 1\right) \cup \left(2, \infty\right)