If M is the midpoint then segment CM and segment MG are equal. So 6x - 15 = 4x + 1.
6x - 15 = 4x + 1
-4x +15 -4x +15
(Move all the x’s to one side the other numbers to the other)
2x = 16
2 2
(Divide both sides by 2)
x = 8
Now just plug in x to find the length of one segment and double it to find the length of CG
6(8) - 15 = 33
33 • 2 = 66
CG = 66