A proportion is an equation that states that two ratios are equal. To determine which option is a proportion, we can simplify the fractions on both sides:
Option 1: \[ \frac{5}{6} = \frac{15}{18} \]
Check if the right side simplifies: \[ \frac{15}{18} = \frac{15 \div 3}{18 \div 3} = \frac{5}{6} \] So, Option 1 is a proportion because both sides are equal, \( \frac{5}{6} = \frac{5}{6} \).
Option 2: \[ \frac{5}{6} = \frac{20}{18} \]
Check if the right side simplifies: \[ \frac{20}{18} = \frac{20 \div 2}{18 \div 2} = \frac{10}{9} \] Since \( \frac{5}{6} \neq \frac{10}{9} \), Option 2 is not a proportion.
Therefore, Option 1 is the proportion.