Geometry question. Please help?

(puu.sh)

1 Answer
Feb 16, 2018

x = 5, bar(BC) = 24

Explanation:

Given : AD is angular bisector of hatA

Using angle bisector theorem,

(BD) / (AB) = (CD) / (AC)

(2x - 1) / 9 = (cancel(3) x) / cancel(15)^color(red)5 = x / 5

(2x - 1) / x = 9/5

2 - 1/x = 9/5

1/x = 1/5, color(green)(x = 5

BC = BD + CD = (2x - 1) + 3x = 10 - 1 + 15 = 24