Add or subtract. 3. \( \frac{1}{4}+\frac{3}{8} \) 5. \( -\frac{2}{3}+\frac{1}{2} \)

To add \( \frac{1}{4}+\frac{3}{8} \), you first need a common denominator. The least common denominator (LCD) of 4 and 8 is 8. Convert \( \frac{1}{4} \) to eighths: \( \frac{1}{4} = \frac{2}{8} \). Now, you can add: \( \frac{2}{8} + \frac{3}{8} = \frac{5}{8} \). For \( -\frac{2}{3}+\frac{1}{2} \), the common denominator of 3 and 2 is 6. Convert both fractions: \( -\frac{2}{3} = -\frac{4}{6} \) and \( \frac{1}{2} = \frac{3}{6} \). Now, add them together: \( -\frac{4}{6} + \frac{3}{6} = -\frac{1}{6} \). So, the answers are \( \frac{5}{8} \) and \( -\frac{1}{6} \)!