In the given image, we see two right triangles sharing a common height, and both triangles seem to be similar because corresponding angles are congruent. The lengths of the bases of the triangles are expressed algebraically: $2x + 1$ and $3x - 5$.

To solve this:

1. Identify the triangles:

   • The two triangles are right-angled.
   • There are two sets of corresponding sides: one on the base and the hypotenuse.
   • The red markings on the hypotenuse indicate that the two hypotenuses of the smaller triangles are equal, confirming the triangles are similar by AA similarity (angle-angle similarity).

2. Use triangle similarity:

   • Since the triangles are similar, the ratio of corresponding sides should be equal.

   $\frac{\text{Base of smaller triangle}}{\text{Base of larger triangle}} = \frac{\text{Height of smaller triangle}}{\text{Height of larger triangle}} = \frac{\text{Hypotenuse of smaller triangle}}{\text{Hypotenuse of larger triangle}}$

   From the diagram, the bases are $2x + 1$ (smaller triangle) and $3x - 5$ (larger triangle).

   Therefore, the ratio of the sides becomes: $\frac{2x + 1}{3x - 5}$

   If the heights and hypotenuses are proportional by the same factor, you could set up a proportionality equation to solve for $x$.

Would you like to proceed with solving for $x$ or need further clarification on the relationships between the triangles?