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?

M + 9 = 13 or 13 - 9 = m

Therefore, m must equal 4

m = 4

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