I see that the uploaded image contains various exercises. I'll start solving the problems step by step. Let me solve problem 12 first and then proceed to others unless you request a specific one.

Problem 12:

The diagram involves a triangle with an angle bisector. The segments divided by the angle bisector are proportional: $\frac{x + 11}{3x + 1} = \frac{1}{1}.$

1. Cross multiply: $x + 11 = 3x + 1.$

2. Rearrange terms to isolate $x$: $11 - 1 = 3x - x.$ $10 = 2x.$

3. Solve for $x$: $x = 5.$

Would you like me to proceed with problems 13, 14, or others? Let me know!