What is the formula for the area A of a circle in terms of the radius r?

Complete the standard form of the equation that represents the quadratic relationship displayed above, where a, b, and c are rational numbers.

Suppose that in 2008 , 840,800 citizens died of a certain disease assuming the population of teh country is 399 miliion, what is the mortality rate in units of deaths per 100,000 people?

Awater truck is filling a swimming pool. the equation that represents this relationship is y=19.75x where y is the number of gallons of water in the pool and x is the number of minutes the truck has been filling the pool.