我想问一下原理

问题如下：

4. Based on the MM propositions with corporate taxes, Garth’s cost of equity after the debt issuance is closest to:

选项：

10.00%.

10.85%.

11.33%.

解释：

C is correct.

$r_e=r_0+(r_0-r_d)(1-t)(\frac DE)$

${l}V_U=\frac{EBIT(1-t)}{r_0}=\frac{400,000(1-0.30)}{0.10}=2,800,000\\V_L=V_U+tD=(2.8million)+(0.30)(1million)=3.10million\\E=V_L-D=(3.10million)-(1million)=2.10million$

$r_e=r_0+(r_0-r_d)(1-t)(\frac DE)$ = $10+(10-6)(1-0.30){(\frac1{2.10})}=10+1.33=11.33\%$