Final answer:
Asa's weekly allowance can be found by setting up an equation where A represents his allowance. After spending half and earning $8 by washing the car, he ended up with $18. Solving for A, it's determined that Asa's weekly allowance is $20.
Step-by-step explanation:
The subject of the question is Mathematics, and it appears to be at a Middle School level. The student is asking to determine Asa's weekly allowance based on the given scenario. Asa spent half of his weekly allowance at the movies and earned an additional $8 by washing the car. We know he ended up with $18. To find Asa's weekly allowance, let's denote the allowance as 'A'. If Asa spent half of A at the movies, he was left with A/2. After washing the car, he had (A/2) + $8, which we are told equals $18. So we write the equation:
(A/2) + $8 = $18
To solve this, first subtract 8 from both sides of the equation:
(A/2) = $10
Then, multiply both sides by 2 to find A:
A = $20
Therefore, Asa's weekly allowance is $20.