From the second:
2x-y=4
x=(4+y)/2 and applying this to first:
4+y+3y=12
4y+4=12
4y=8
y=2 and since x=(4+y)/2, x=3 so
x+y=2+3=5
I think your right,It would be 81.6.
Hope this helps. :D
Answer:

Step-by-step explanation:
Given



Required
Find r
From the question, we understand that G is a point between D and M:
This implies that:

Substitute values for DM, DG and GM

Collect Like Terms


Solve for r

