l ule glving cost per ton. hthe first year. (Show computations by 7-Adjustment of Depreciable Base. A truck was acquired on July 1, 2015, at a cost of $189,000. The truck had a six-year useful life and an estimated salvage value of $21,000. The straight-line method of depreciation was used. On January 1, 2018, the truck was overhauled at a cost of $17,500, which extended the useful life of the truck for an additional two years beyond that originally estimated (salvage value is still estimated at $21,000). In computing depreciation for annual adjustment purposes, expense is calculated for each month the asset is owned. Instructions Prepare the appropriate entries for January 1, 2018 and December 31, 2018