3. In the figure below, E is on AD and C is on BD. The dimensions given are in meters. What is the length, in meters, of CD?
A. 2,640
B. 2,784
C. 3,960
D. 4,400
E. 5,840

3 In the figure below E is on AD and C is on BD The dimensions given are in meters What is the length in meters of CD A 2640 B 2784 C 3960 D 4400 E 5840 class=

Respuesta :

Answer:

C. 3,960

Step-by-step explanation:

∆ADB ~ ∆EDC. Therefore,

[tex] \frac{AB}{EC} = \frac{DB}{DC} [/tex]

[tex] \frac{2,000}{1,200} = \frac{2,640 + x}{x} [/tex] (substitution)

Solve for x

[tex] \frac{5}{3} = \frac{2,640 + x}{x} [/tex]

Cross multiply

[tex] 5*x = 3(2,640 + x) [/tex]

[tex] 5x = 7,920 + 3x [/tex]

5x - 3x = 7,920

2x = 7,920

x = 7,920/2

x = 3,960 meters