TU is given to be 3x in the problem, and UV is x+10. We need to find what TU is exactly without the x. To do that, we will find the value of x.
The line is TV, with a midpoint of U. The line is broken down to 2 other lines equally: TU and UV. To find the value of x, we will set them equal.
TU=UV
3x=x+10
Subtract x to both sides:
2x=10
Divide 2 to both sides:
x=5
Now we will put 5 in for x.
TU=3x
TU=3(5)
TU=15
Hope this helped!