All the angles in a triangle equal 180 degrees. 
So, 2x, 3x-11, and 2x+9= 180
2x+3x-11+2x+9=180 
Combine like terms. 
7x-2=180 
Add two to both sides. 
7x=182
Divide by 7 into both sides. 
x=26 
Now, plug in x.
2x
2(26)= 52
3x-11
3(26)-11
78-11= 67
2x+9
2(26)+9
52+9= 61
2x is the smallest angle. 52<61
I hope this helps!
~kaikers