Really struggling with this one. Can someone help please?

Answer:
12
Step-by-step explanation:
M is in the middle between S and T we know 2x+6 has to be the same as 3x+3 if 3x is one more x then 2x then we do 6-3 that eqauls 3 so X=3 and 2*3=6 and 6+6= 12.
Hey there! :D
Answer:
[tex]\huge\boxed{SM = 12}[/tex]
SM = 2x + 6
MT = 3x + 3
M is the midpoint of SM
Write an expression to represent the length of ST:
ST = SM + MT
ST = 2x + 6 + 3x + 3
Combine like terms:
ST = 5x + 9
Since ST = 2(SM), set up another equation:
5x + 9 = 2(2x + 6)
5x + 9 = 4x + 12
Isolate the "x" variable:
5x - 4x = 12 - 9
x = 3.
Substitute in this value of "x" into the equation for SM:
2(3) + 6 = 12.