Question

In the diagram below, ABC ~ DEC. What is the value of x?

A. 2

B. 3.5

C. 2.5

D. 3​

Answer 1

25/5=(18-x)/x
5x=18-x
6x=18
x=3

Answer is (D).

Answer 2

x = 3

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.

`(ec)/(bc) = (ed)/(ba) \\ (25)/(5) = (18 - x)/(x) \\ (18 - x)/(x) = 5 \\ 18 - x = 5x \\ 18 = 5x + x \\ 6x = 18 \\ x = (18)/(6) \\ = 3`