1. ## ratios

2. Originally Posted by sanee66
$AB : DE = 5 : 4$

$\Rightarrow \frac {AB}{DE} = \frac {5}{4}$

$\Rightarrow \frac {x + 16}{16} = \frac {5}{4}$

$\Rightarrow \boxed { x = 4 }$

$AC : DF = 5 : 4$

$\Rightarrow \frac {AC}{DF} = \frac {5}{4}$

$\Rightarrow \frac {y + 7}{20} = \frac {5}{4}$

$\Rightarrow \boxed { y = 18 }$

Thus we have $x : y = \frac {x}{y} = \frac {4}{18} = \frac {2}{9} = \boxed { 2 : 9 }$