In triangle ABC, D is the centroid and M is the midpoint of segment AC. If BD=x+9 and DM=6, find MB. Answer choices: 9 , 3, or 18.

This is almost identical to the question you posed in

http://www.jiskha.com/display.cgi?id=1225892455

follow the method I described there.

its B

To find MB, we can use the properties of a centroid.

First, let's recall that in a triangle, the centroid divides each median into two segments with a ratio of 2:1.

In this case, we are given that DM = 6. Therefore, the length of BD can be calculated as 2 * DM = 2 * 6 = 12.

Now, we can set up an equation to find the length of MB.

BD + DM = BM

Substituting the given values:

12 + 6 = BM

BM = 18

Therefore, MB is equal to 18.