<PRE><B>Question 1026194</B>
let x equal his allowance.


he earns 9 dollars for washing the family car.


his total intake is x + 9.


he spend half of his allowance going to the movies.


this means he spent 1/2 * x going to the movies.


he has 15 dollars left.


you get:


x + 9 - 1/2 * x = 15.


combine like terms to get 1/2 * x + 9 = 15.


subtract 9 from both sides of the equation to get 1/2 * x = 15 - 9


simplify to get 1/2 * x = 6.


multiply both sides of this equation by 2 to get x = 6 * 2.


simplify to get x = 12.


his allowance must have been 12 dollars.


he washes the family car and earns 9 dollars.


he now has 21 dollars.


he spends half of his allowance, which is 12 dollars, on the movies which means he spent 6 dollars on the movies.


he now has 21 - 6 = 15 dollars.


looks good to me.


his allowance had to be 12 dollars.


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