set up the proportion, cross multiply, and solve for the missing length.
[tex]\frac{BA}{BE} = \frac{DC}{DE}[/tex]
[tex]\frac{6}{3} = \frac{9}{DE}[/tex]
6(DE) = 3(9)
DE = [tex]\frac{3(9)}{6} = \frac{9}{2} = 4.5[/tex]
Answer: 4.5
