i need the formula to solve this problem I'm sruggling understanding how to get the accumulated depreciation.

University Car Wash purchased new soap dispensing equipment that cost $240,000 including installation. The company estimates that the equipment will have a residual value of $30,000. University Car Wash also estimates it will use the machine for six years or about 12,000 total hours. Actual use per year was as follows: 2. Prepare a depreciation schedule for six years using the double-declining-balance method. (Do not round your intermediate calculations.) \begin{tabular}{|c|c|c|c|c|} \hline \multicolumn{5}{|c|}{ UNIVERSITY CAR WASH } \\ \hline \multicolumn{5}{|c|}{ Depreciation Schedule-Double-Declining-Balance } \\ \hline \multicolumn{5}{|c|}{ End of Year Amounts } \\ \hline Year & \multicolumn{2}{|c|}{ Expense } & \begin{tabular}{l} Accumulated \\ Depreciation \end{tabular} & Book Value \\ \hline 1 & $ & 80,000 & 80,000 & 160,000 \\ \hline 2 & & 53,333 & & \\ \hline 3 & & & & \\ \hline 4 & & & & \\ \hline 5 & & & & \\ \hline 6 & & & & \\ \hline Total & $ & 133,333 & & \\ \hline \end{tabular}