Chapter 7 - Algebraic Fractions - 7.3 - Adding and Subtracting Algebraic Fractions - Problem Set 7.3 - Page 291: 8

$-\frac{2}{x^{2}}$

By inspection, we see that there is a common denominator of $5x^{2}$. Therefore, we obtain: $\frac{12}{5x^{2}}-\frac{22}{5x^{2}}$ $=\frac{12-22}{5x^{2}}$ $=\frac{-10}{5x^{2}}$ $=\frac{-2}{x^{2}}$ $=-\frac{2}{x^{2}}$