Question

A, C, and D are collinear, and C is between A and D.If AC = 3x + 1, CD = 15, and AD = 10x - 5, what is the value of x?

Answer 1

1) Sketching it

Since the line segment AD = 10x -5 and AC= 3x +1 and CD= 15

According to the Segment Addition postulate we can write:

3x+1+15=10x-5 Combining like terms

3x +16 = 10x -5 Subtract 16 from both sides

3x = 10x-5-16 Subtract 10x from both sides

3x-10x =-21

-7x = -21

7x=21 Dividing by 7 on both sides

x=3