geometry
posted by _ on .
M is the midpoint of segment AB, AM=2x+4 and AB=12x+4. What is the value of MB? Show your work for credit.

I don't need the credit, you do.
If M is the midpoint, AM must equal MB, and both must be half of AB. Tey tell you that AB = 12x = 4.
Therefore 2x + 4 = 6x + 2
Solve for x and complete the problem. 
They tell you that AB = 12x + 4.
Therefore 2x + 4 = 6x + 2
x = 0.5
AM = MB = 5