The midpoint formula of points

Question

I need to find a midpoind of u where T is 3x+9, v = 14+2x, and u is located in the middle of T and V.

Answer 1

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

as we know u is a midpoint, UV = TU, so UV = (x-5) / 2

TU + UV = TV

(x-5) / 2 + (x-5) /2 = 2 (x-5) /2 = x-5 = TV