In the diagram below, ABC ~ DEC. What is the value of x?
A. 2
B. 3.5
C. 2.5
D. 3

Answer:
x = 3
Step-by-step explanation:
Please refer to the attached photo. (Apologies for the terrible drawing.)
Since we know triangles ABC and DEC are similar, we can use the ratio method to find x.
[tex] \frac{ec}{bc} = \frac{ed}{ba} \\ \frac{25}{5} = \frac{18 - x}{x} \\ \frac{18 - x}{x} = 5 \\ 18 - x = 5x \\ 18 = 5x + x \\ 6x = 18 \\ x = \frac{18}{6} \\ = 3[/tex]