Use a common denominator to write an equivalent fraction for each fraction. \( \begin{array}{ll}\text { 1. } \frac{1}{2} \text { and } \frac{3}{8} & \text { 2. } \frac{7}{9} \text { and } \frac{2}{3}\end{array} \)

To find equivalent fractions using a common denominator, we first identify the least common multiple (LCM) of the denominators. For \( \frac{1}{2} \) and \( \frac{3}{8} \), the LCM of 2 and 8 is 8. Thus, we convert \( \frac{1}{2} \) to \( \frac{4}{8} \) (by multiplying both the numerator and denominator by 4), making the equivalent fractions \( \frac{4}{8} \) and \( \frac{3}{8} \). For \( \frac{7}{9} \) and \( \frac{2}{3} \), the LCM of 9 and 3 is 9. We keep \( \frac{7}{9} \) as is and convert \( \frac{2}{3} \) to \( \frac{6}{9} \) (by multiplying by 3). The equivalent fractions are now \( \frac{7}{9} \) and \( \frac{6}{9} \).