From this picture,

Find the length of line DG.

Line AG= 13x-3

line BG= 4x + 3

line CG= 3x + 14

line EG= 11

I figured BG = CG, so I set them equal and got x= 11.

I plugged the x value into everything, reviewed the centriod theorem formulas (e.g. line AD = AG )