 
Jason S. answered  10/14/13
Tutor
                    
        4.9
        (116)
            My goal is the success of my students. Knowledge-Patience-Honesty
TV = 3x+9 - (14+2x)
TV = 3x + 9 -14 - 2x
TV =  x - 5 
U = ((3x + 9) + (14 + 2x)) / 2 
U = (5x + 23) / 2
TU = (2(3x + 9) / 2) - (5x+23)/2 
TU = (6x + 18 - 5x -23) /2 
TU = (x - 5) / 2
Since U is the midpt, UV = TU, so UV = (x-5) / 2
TU + UV = TV 
(x-5) / 2 + (x-5) /2 = 2 (x-5) /2 = x-5 = TV
Use a number for x.  Let's use 10.
T is 39, V = 34
U = (39 + 34)/2 = 73/2 = 36.5
TV = 39-34 = 5
TV from our equation is x-5.  10 - 5 = 5.   Good.
TU and UV = (x-5) / 2.   (10-5) /2 = 5/2.
(39-34)/2 = 5/2   Good.
 
     
             
 
                     
                    