Note that you are given the pre-tax cost of debt at different levels of financial leverage, but must calculate the after-tax cost of debt. Also, you will need to estimate the beta at various levels of financial leverage using the Hamada Model. From there you will need to use the CAPM to calculate the cost of equity at each level of financial leverage. Once you have done that, the value of the firm is just the discounted present value of the expected Free Cash Flows cash flow at the implied WACC. Note that we are assuming no growth in the FCFs, so the discounting is done with the regular perpetuity model.

A B D E F G | K M. L 0.28 O N Mil. Shares FCF in mil. 48 Tax Rate 10 Pre-tax After-tax w. Value of Firm S&P Bond Rating AAA AA+ S&P500 10 yr. T-Note I'm 10.00% 3.47% rd 1.91% rs WACC B 1.0500 W, 1.000 0.935 0.870 AA 0.000 0.065 0.130 0.195 0.260 0.325 0.805 AA- A+ 0.740 0.675 0.610 A A A- 0.390 0.455 0.545 rd 2.65% 2.96% 3.25% 3.56% 3.75% 3.89% 4.01% 4.65% 5.25% 6.23% 7.22% 7.84% 9.12% 10.56% 12.62% 18.45% BBB+ BBB 0.520 0.480 BBB- 0.585 0.650 0.415 0.350 CCC+ 0.715 0.285 0.220 0.780 CCC - CC 0.155 0.845 0.910 C 0.090 0.025 0.975 D A B D E F G | K M. L 0.28 O N Mil. Shares FCF in mil. 48 Tax Rate 10 Pre-tax After-tax w. Value of Firm S&P Bond Rating AAA AA+ S&P500 10 yr. T-Note I'm 10.00% 3.47% rd 1.91% rs WACC B 1.0500 W, 1.000 0.935 0.870 AA 0.000 0.065 0.130 0.195 0.260 0.325 0.805 AA- A+ 0.740 0.675 0.610 A A A- 0.390 0.455 0.545 rd 2.65% 2.96% 3.25% 3.56% 3.75% 3.89% 4.01% 4.65% 5.25% 6.23% 7.22% 7.84% 9.12% 10.56% 12.62% 18.45% BBB+ BBB 0.520 0.480 BBB- 0.585 0.650 0.415 0.350 CCC+ 0.715 0.285 0.220 0.780 CCC - CC 0.155 0.845 0.910 C 0.090 0.025 0.975 D