He paid 25% of the new home price because 100 - 75 = <<100-75=25>>25

He paid $125,000 towards the new home because 500,000 x .25 = <<500000*.25=125000>>125,000

Therefore he paid $100,000 for his first home because 125,000 / 1.25 = <<125000/1.25=100000>>100,000

# Answer

100000
<|im_start|>system
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<|im_start|>user
Tommy's home is worth 25% more than he bought it for. He sells it and buys a new house that costs $500,000. If he had to take a loan for the 75% he can't pay, how much did he buy his first house for?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
100000
Tommy's home is worth 25% more than he bought it for. He sells it and buys a new house that costs $500,000. If he had to take a loan for the 75% he can't pay, how much did he buy his first house for?
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