Respuesta :

answer is C. 22

if you subtract 15 by 10, you get 5. so you can also subtract 27 by 5 and get 22

∆ABC is similar to ∆DEF (SAS),

AB/DE = AC/DF
27/x = 15/10
15x = 270
x = 18

The length of DE is 18 units.