Answer:
Step-by-step explanation:
Collinear points are points are points that lies on the same line. If point B is between A and C, then AC = AB+BC
Given AC = 21x, AB = 11 and BC = 11x-1, in order to find the value of x, we will substitute the given parameters in the relationship above to have;
[tex]21x = 11+11x-1\\21x = 10+11x\\[/tex]
Subtracting 11x from both sides;
[tex]21x-11x = 10+11x-11x\\10x = 10\\x = 1[/tex]
Since AC = 21x
substituting x = 1 into AC,
AC = 21(1)
AC = 21
