please answer both parts, they go together

Without leverage, Impi Corporation will have net income next year of $9.0 million. If Impi's corporate tax rate is 21% and it pays 6% interest on its debt, how much additional debt can Impi issue this year and still receive the benefit of the interest tax shield next year? (Note: Assume Impi's revenues exceed \$26 million, and that interest tax deductions are limited to 30% of EBIT under the TCJA.) The debt is $ million. (Round to three decimal places.) Summit Builders has a market debt-equity ratio of 0.55, a corporate tax rate of 30%, and pays 6% interest on its debt. By what amount does the interest tax shield from its debt lower Summit's WACC? WACC is lowered by \%. (Round to two decimal places.)