Kendra’s age is half the age of Justin. Kendra is 13 years old. Which of the following equations represents Justin’s age, a ?

13a = 2

2a = 13

a + 1/2 = 13

1/2a = 13

1 answer

Kendra is 13 years old, and her age is half of Justin's age. We can represent Justin's age with the variable \( a \).

Since Kendra's age is half of Justin's, we can write the equation as:

\[ 13 = \frac{1}{2}a \]

To isolate \( a \), we can multiply both sides of the equation by 2:

\[ 2 \times 13 = a \]

This simplifies to:

\[ a = 26 \]

Now, looking at the options you provided:

  1. \( 13a = 2 \) - This does not represent the relationship correctly.
  2. \( 2a = 13 \) - This is the inverse of what we need (it would imply that if you double Justin's age, you get Kendra's age, which is incorrect).
  3. \( a + \frac{1}{2} = 13 \) - This does not represent the situation correctly.
  4. \( \frac{1}{2}a = 13 \) - This is actually a rearranged form of the initial relationship and is correct.

Therefore, the correct equation that represents Justin's age \( a \) is:

\[ \frac{1}{2}a = 13 \]

So, the correct answer is the fourth option: \( \frac{1}{2}a = 13 \).