please explain

In 2010 Casey made a taxable gift of $5 million to both Stephanie and Linda (a total of $10 million in taxable gifts). Calculate the amount of gift tax due this year and Casey's unused applicable credit under the following alternatives. (Refer to Exhibit 25-1 and Exhibit 25-2.) Note: Enter your answers in dollars, not millions of dollars. Leave no answer blank. Enter zero if applicable. Problem 25-49 Part a (Static) This year Casey made a taxable gift of $1 million to Stephanie. Casey is not married, and the 2010 gift was the only other taxable gift he has ever made. EXHIBIT 25-1 Unified Transfer Tax Rates* *The applicable credit and exemption are zero for estates that opted out of the estate tax in 2010. EXHIBIT 25-2 The Exemption Equivalent / Applicable Exclusion Amour estate tax in 2010