16. \( \frac{4}{5}=\frac{x}{15} \)

To solve the equation \( \frac{4}{5}=\frac{x}{15} \), you can use cross-multiplication. Multiply across the equals sign: \( 4 \times 15 = 5 \times x \). This gives you \( 60 = 5x \). Now, divide both sides by 5 to isolate \( x \): \( x = \frac{60}{5} = 12 \). So, \( x = 12 \). To check your work, substitute \( x \) back into the original equation: \( \frac{12}{15} \) simplifies to \( \frac{4}{5} \). Success! You’ve confirmed your solution is correct.