Write the pair of fractions as a pair of fractions with a common denominator. (4.NF.A.1) 12. \( \frac{3}{10} \) and \( \frac{2}{5} \)

To rewrite \( \frac{3}{10} \) and \( \frac{2}{5} \) with a common denominator, we first need to find the least common denominator (LCD). The denominators are 10 and 5. The LCD of 10 and 5 is 10. Now, \( \frac{3}{10} \) stays the same because it already has the LCD. For \( \frac{2}{5} \), we can convert it to a fraction with a denominator of 10 by multiplying both the numerator and denominator by 2, giving us \( \frac{2 \times 2}{5 \times 2} = \frac{4}{10} \). So, the pair of fractions with a common denominator is \( \frac{3}{10} \) and \( \frac{4}{10} \).