During the synthesis stage of the cell cycle, a cell makes (replicates its own) DNA.
Economic profits equals total revenues minus the sum of explicit costs and implicit costs. Since explicit costs are already subtracted when arriving at the accounting profit, we can find economic profit by subtracting the implicit costs from the accounting profit.
Implicit costs also represent the divergence between economic profit (total revenues minus total costs, where total costs are the sum of implicit and explicit costs) and accounting profit (total revenues minus only explicit costs).