Tom 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?

Let x = Tom’s allowance
Let x/2 = the amount he spent going to the movies.
So x – x/2 = the amount he has left after she went to the movies
he washed the car and earned nine dollars, so you’d add that amount in
x – x/2 + 9
the amount he has left over is 13 dollars
x – x/2 + 9 = 13
Now you solve for x
x – x/2 + 9 = 13
x/2 + 9 = 13
x/2 = 4
x = 8
His allowance is $8
To check your work, plug 8 into the equation:
8 – 8/2 + 9 = 13
8 – 4 + 9 = 13
13 = 13