## Elementary Algebra

$= \frac{5-7x^{2}}{x^{4}}$
1) Multiply a fraction with the other denominator to obtain a common denominator between the two fractions. In this case, we only need to multiply the second fraction by $x^{2}/x^{2}$ 2) Subtract $= \frac{5}{x^{4}} - \frac{7}{x^{2}}$ $= \frac{5}{x^{4}} - \frac{7x^{2}}{x^{4}}$ $= \frac{5-7x^{2}}{x^{4}}$