The centroid of a triangle is the point of interection of all the three medians and they have the following property:
Then, we have the following result:
By substituting the given information into this equation, we have
or equivalently,
Now, by multiplying both sides by 2x-1, we get
and by dividing both sides by 2, we obtain
We can obtain this last result if we distribute the number 2 into the parenthesis and divide the result by 2, that is,
Now, by subtracting x to both sides of the last resutl, we have
and by adding 1 to both sides, we obtain
or equivalently, x=5.
Finally, in order to obtain AN, we must substitute the last result into the expression for AN. It yields,
Therefore, the answer is: AN = 9