Answer:
4
Step-by-step explanation:
RS + ST = RT
=> 3x-8 + x = 2x
4x - 8 = 2x
Subtract 2x from both the sides,
4x - 2x - 8 = 0
2x - 8 = 0
Add 8,
2x = 8
Divide by 2,
x = 8/2 = 4
Length of line segment ST = x = 4
