X^2-18-6 completing the square

A road has a 16.7% grade. Why might we want to warn drivers of a grade like this?

C (x) = 0.000002x3 - 0.03x2 + 400x + 80,000 where C (x) denotes the total cost incurred in producing x sets. Find the level of production that will yield a maximum profit for the manufacturer. Hint: Use the quadratic formula

Which set of ordered pairs represents a linear function? A. (-8,-15), (-4,-12), (4,-6), (16,-3) B. (-8,15), (-4,12), (4,-6), (16,3) C. (-8,-15), (-4,-12), (4,-6), (16,3) D. (8,15), (-4,-12), (4,6), (16,3)

What is 3/9 simplified to?

Simplifying radicals √112

A newspaper reporter wants to know how popular the hobby of bird watching is in the city. He asked people at the local bird refuge if they watched birds as a hobby. Which of the following best explains whether the reporters data is valid or not?

I am very confused on how to figure out if y = 3/4x is proportional?

Alison wants to buy a mountain bike for $339.12. If she saves $28.26 each month, in how many months will she be able to buy the bike?

At 12 o'clock the temperature was 7°C. The temperature decreased by - 20°C. What is the new temperature?

Ashleys rentals charges $27.50 per hour to rent a surfboard and a wetsuit. Darlas surf shop charges $23.25 per hour to rent a surfboard plus $17 extra for a wetsuit.