Geometry

Question Analysis：
This problem applies the trapezoid midsegment formula using three expressions.
Main focus: solving a linear equation.

Key Concept Explanation：
Midsegment = (Base₁ + Base₂) ÷ 2

Step-by-Step Solution：
Set up equation:
8x − 5 = [(3x + 1) + (5x − 3)]/2
8x − 5 = (8x − 2)/2
8x − 5 = 4x − 1
4x = 4
x = 1

Common Mistakes：
Adding expressions ...