Answer
CD =2
DB = 3
Work Step by Step
We use the theorem recommended by the book to obtain:
$\frac{CD}{AC} = \frac{DB}{AB} \\ \frac{CD}{4} = \frac{5-CD}{6} \\ CD = 2 $
Using the original proportion, we have:
$\frac{2}{4} = \frac{DB}{6} \\ DB =3$
