Geometry

Question Analysis:
This algebra-geometry hybrid question requires solving for a variable using congruent triangles.

Key Concept Explanation:
Corresponding sides of congruent triangles are equal, enabling equation setup.

Step-by-Step Solution:
Since ⊿PQR ≅ ⊿STU, PQ ≅ ST.
Set expressions equal: 2x + 3 = 15
Solve: 2x = 12 → x = 6.

Common Mistakes:
Incorrectly setting up the equation (e.g., 2x =...