If C is a point between AB then we can write AC + CB = AB
Same way we can write tu + ub = tb
tu = 4x - 1 , ub = 2x - 1 and tb = 5x
So we can write it as
[tex]4x - 1+ 2x - 1 = 5x[/tex]
[tex]6x - 2 = 5x[/tex]
[tex]6x - 5x = 2[/tex]
[tex]x = 2[/tex]
So x is = 2.