Which expression is equivalent to a^-x?

Three baby penguins and their father were sitting on an iceberg 0.50.50, point, 5 meters above the surface of the water. the father dove down 4.74.74, point, 7 meters from the iceberg into the water to catch dinner for his kids. what is the father penguin's position relative to the surface of the water?

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To finance her community college education, sarah takes out a loan for $2900. after a year sarah decides to pay off the interest, which is 4% of $2900. how much will she pay