text: ## Basic College Mathematics (10th Edition)
  
  $y = 12$ cm $z = 6$ cm
  1. Solve for $y$ $\frac{10}{15} = \frac{y}{18}$ $\frac{180}{15} = y$ $y = 12$ cm 2. Solve for $z$ $\frac{10}{15} = \frac{z}{9}$ $z = \frac{90}{15}$ $z = 6$ cm