Final answer:
The company's market value debt-equity (D/E) ratio is approximately 0.56.
Step-by-step explanation:
To calculate the market value debt-equity (D/E) ratio, we can use the formula: 
. The weighted average cost of capital (WACC) is the weighted average of the cost of equity and the after-tax cost of debt. The formula for WACC is: 
, where E is the market value of equity, D is the market value of debt, 
 is the total market value (equity + debt), 
 is the cost of equity,
 is the cost of debt, and 
 is the corporate tax rate.
Given that WACC is 7.5%, Re is 10%, Rd is 5%, and Tc is 35%, we can rearrange the WACC formula to find the market value debt-equity (D/E) ratio. Solving for 
, we get 
. Substituting in the values, we find 
, which results in approximately 0.56. Therefore, the company's market value debt-equity (D/E) ratio is approximately 0.56.