Give the step-by-step reasoning process and then the final answer. Delores has some money. She buys a computer for $400 and a printer for $40. If she has $10 left, how much money, in dollars, did Delores have at first?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
The computer and printer cost 400 + 40 = 440 dollars. Delores had 440 + 10 = 450 dollars at first.
The final answer: 450.