Can anybody find the answers to any of these please

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?

Bring the fraction a/a-4 to a denominator of 16-a^2

With this problem-elena cycled to school. find the distance travelled by elena if her bicycle wheels rotated 840 times and the radius is 0.25 m.