Sam spent half of his allowance going to the movies. He washed the family car and earned 9 dollars. What is his weekly allowance if he ended with 13 dollars?

Step 1 ：Sam spent half of his allowance going to the movies. He washed the family car and earned 9 dollars. What is his weekly allowance if he ended with 13 dollars?

Step 2 ：To solve for A, we can subtract 9 from both sides of the equation to get \(0.5A = 13 - 9\).

Step 3 ：Then, we can multiply both sides of the equation by 2 to solve for A.

Step 4 ：The solution to the equation is \(A = 8\). This means that Sam's weekly allowance is 8 dollars.

Step 5 ：Final Answer: Sam's weekly allowance is \(\boxed{8}\) dollars.