To find Justin's age, we start with the information given: Kendra’s age is half the age of Justin, and Kendra is 13 years old.
We can set up the equation based on the relationship between their ages:
- Let \( a \) be Justin's age.
- According to the problem, Kendra's age (13) is half of Justin's age, so we can write the equation as: \[ 13 = \frac{1}{2} a \]
To isolate \( a \), you can multiply both sides by 2: \[ 2 \times 13 = a \] \[ 26 = a \]
So, Justin's age is 26.
The correct equation that represents Justin's age \( a \) based on the information given is: \[ \frac{1}{2} a = 13 \]
Thus, the correct response is: Start Fraction 1 over 2 End Fraction a equals 13.