1. Write the equivalent ratios. \begin{tabular}{|l|l|l|l}\hline a. \( \frac{3}{5}=\frac{18}{} \) & b. \( 2: 3=18: \) & c. \( \quad \) to \( 45=2109 \) & d. \( 12: 30=\ldots \) to 5\end{tabular}

To find the equivalent ratios, let's dive into each of them! a. To find the missing value, set up the proportion: \( \frac{3}{5} = \frac{18}{x} \). Cross-multiply and solve: \( 3x = 90 \), so \( x = 30 \). Thus, the equivalent ratio is \( \frac{3}{5} = \frac{18}{30} \). b. For \( 2:3=18:y \), this means \( \frac{2}{3} = \frac{18}{y} \). Cross-multiply: \( 2y = 54 \) leads us to \( y = 27 \). Therefore, the equivalent ratio is \( 2:3 = 18:27 \). c. In the ratio \( \quad \) to \( 45=2109 \), we want to find the first term. If we set it as \( x:45=2109 \), we have \( x = \frac{2109 \times 45}{45} = 2109 \). Hence, the unknown is 2109. d. For \( 12:30=\ldots \) to 5, we know that \( 12/x = x/5 \). Cross-multiply: \( 12 \cdot 5 = 30x \), so \( 60 = 30x\, \Rightarrow x = 2 \). Therefore, \( 12:30 = 2:5 \).