An aircraft factory manufactures airplane engines. The unit cost C (the cost in dollars to make each airplane engine) depends on the number of engines made. If r engines are made, then the unit cost is given by the function () - 04x²-96x+24,865. What is the minimum unit cost?
Do not round your answer.

The diameter of the moon is about 3500 km. approximate the surface area of the moon using the formula for the surface area of a sphere, s = 4? r^2. write your answer in scientific notation.

Martha is training for a duathlon, which includes biking and running. she knows that yesterday she covered a total distance of over 55.5 miles in more than than 4.5 hours of training. martha runs at a speed of 6 mph and bikes at a rate of 15.5 mph.

Luigi is the first person to finish a 5k race and is standing 13 feet beyond the finish line. another runner, mario, is still running the race and has approximately 24 feet before he reaches the finish line. what is the distance between mario and luigi? explain through words, numbers or pictures how you found the answer.