In triangle ABC, DEAC. If AD=12, BD=3, and CE=10, find BE.

BE = 2.5

Step-by-step explanation:

Remark

Use triangles ABC and DEB.

Formula

AB/DB = BC / BE

Givens

Solution

15/3 = (10 + x)/x              Cross multiply

15x = 3(10 + x)                Remove the brackets

15x = 30 + 3x                 Subtract 3x from both sides.

15x - 3x = 30                  Combine

12x = 30                         Divide by 12

x = 30/12

x = 2.5

1. d.90

2. e. none of these (80)

3. a. 0

4. b. 6

5. e. none of these (10)

6. a. 5