Quandaries
and Queries 

Question: hey my name is maria..im a student in university...please answer my question as soon as possible... given:x+2y=4...L1 8x=y...L3 Q3)find the coordinates of the centroid of triangle ABC thnx for helping me out 

Hi Maria, I am assuming that ABC is the triangle formed by the lines L1, L2 and L3. From your calculations the point of intersection of L1 and L2 is (2,1). I am going to call this point A. Now solve L1 and L3 to find where they intersect and call that point B. Finally solve L2 and L3 to find their intersection and call this point C. Thus you have the vertices of the triangle. Suppose that you have a triangle with vertices (a_{1}, b_{1}), (a_{2}, b_{2}) and (a_{3}, b_{3}). The centroid of this triangle has xcoordinate
and ycoordinate
Penny 

