Cash-flow equation derivation. Derive the cash-flow equation for EBITDA (Cash flow = EBITDA(1 - tax) + (tax - Depreciation) - WCR - Capex; wher EBITDA = earnings before interest and tax and depreciation and amortization, Tax = marginal tax rate, WCR = change in working capital requirement, and Capex = capital expenditures required to support the project) using the EBIT equation (Cash flow = EBIT(1-Tax) +depreciation - WCR - Capex; where EBIT = earnings before interest and tax, Tax = marginal tax rate, WCR = change in working capital requirement, and Capex = capital expenditures required to support the project). Prove mathematically that both equations are the same.