To solve this problem, let's analyze the given information step-by-step and determine the correct equation representing the number of wheels:
1. Understand the Given Information:
- The total number of seats counted is 20.
- This can be represented by the equation [tex]\( u + b = 20 \)[/tex], where [tex]\( u \)[/tex] is the number of unicycles and [tex]\( b \)[/tex] is the number of bicycles.
- The total number of wheels counted is 28.
2. Determine How Each Type of Vehicle Contributes to the Wheel Count:
- A unicycle, by definition, has only 1 wheel.
- A bicycle has 2 wheels.
3. Formulate the Equation Representing the Wheel Count:
- If there are [tex]\( u \)[/tex] unicycles, they contribute [tex]\( u \)[/tex] wheels in total (since each unicycle has 1 wheel).
- If there are [tex]\( b \)[/tex] bicycles, they contribute [tex]\( 2b \)[/tex] wheels in total (since each bicycle has 2 wheels).
4. Combine the Contributions:
- The total number of wheels is the sum of wheels from unicycles and bicycles.
- Therefore, the equation representing the total number of wheels is [tex]\( u + 2b = 28 \)[/tex].
Given these steps and our analysis, the correct equation representing the number of wheels is:
[tex]\[ \boxed{u + 2b = 28} \][/tex]
This corresponds to option:
A. [tex]\(u + 2 b = 28\)[/tex]
