Question

Find the value of x.
14
3x-12
A
A
21
x = [?]

Answer 1

Explanation:

Set up a ratio.

An angle bisector divides the side opposite it in the same ratio as the two sides defining the angle where the vertex and angle bisector meet.

14/6 = 21 / 3x - 12

Cross multiply

14(3x - 12) = 6*21

Remove the brackets

42x - 168 = 126

Add 168 to both sides

42x = 168 + 126

Combine

42x = 294

Divide by 42

x = 294/42

x = 7