please help me solve c and dmany thanks

TO OIL question Question 13 (answer all parts) GlaxoSmithKline plc is a pharmaceutical company. It is considering the replacement of one of its existing machines with a new model. The existing machine can be sold now for 8,000. The new machine costs 50,000 and will generate free cash flows of 11,416.55 p.a. over the next 6 years. The corporate tax rate is 35%. The new machine has average risk. GlaxoSmithKline's debt-equity ratio is 0.5 and it plans to maintain a constant debt-equity ratio. GlaxoSmithKline's cost of debt is 5.85% and its cost of equity is 13.10%. a) Compute GlaxoSmithKline's weighted average cost of capital. (5 marks) b) What is the NPV of the new machine and should GlaxoSmithKline replace the old machine with the new one? (10 marks) c) The average debt-to-value ratio in the pharmaceutical industry is 20%. What would GlaxoSmithKline's cost of equity be if it took on the average amount of debt of its industry at a cost of debt of 5%? Do this calculation assuming the company does not pay taxes. (10 marks) d) Given the capital structure change in question c), Modigliani and Miller would argue that according to their theory, GlaxoSmithKline's WACC should decline because its cost of equity capital has declined. Discuss. (10 marks)