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In 2004 Elon Musk purchased Tesla Corporation. Once he finalized the takeover Musk purchased equipment at a cost of $520,000. The equipment has an estimated life of 7 years or 90,000 units of product. The estimated salvage value is $45,000. In 2004, 15,000 units of product were produced with this machinery. Determine the following: Book value at the end of 2004 using straight-line depreciation