Please, show the work on this exercise. Thank you

26. Beauty Inc. plans to maintain its optimal capital structure of 40 percent debt, 10 pares stock, and 50 percent common equity indefinitely. The required return on each compen capital is as follows: debt-8 percent: preferred stock-10 percent; common equily Assuming a 21 percent marginal tax rate. what after-tax rate of return must the firm earn on investments if the value of the firm is to remain unchanged? ructure of 40 percent debt, 10 percent preferred equired return on each component source of ming a 21 pers. debt-8 perally indefinitely a structure of 4