A 653000 property is depreciated for tax purposes by its own

A $653,000 property is depreciated for tax purposes by its owner with the straight-line depreciation method. The value of the building, y, after x months of use is given by y = 653,000 1800x dollars. After how many months will the value of the building be $449,600?

Solution

y = 653,000 1800x dollars

let after t many months will the value of the building be $449,600.

then

449600 = 653000 - 1800 t

t = (653000-449600)/1800=113

so 113 months