Susan spent $8 of her allowance going to the movies. she gave the dog a bath and earned $5.00. what is her weekly allowance if she ended up with $20.00

Let x be her weekly allowance.
Susan spent $8 of her allowance going to the movies, so x-8=20. Also she gave the dog a bath and earned $5, so our equation now is x-8+5=20.
Now we can solve for x to get the value of her allowance:





We can conclude that Susan's weekly allowance is $23