An investor invests a total of $15,000 in two banks. One bank pays 4% simple interest, and the other bank pays 2.5% simple interest. The investor earns $472.80 annual interest. Set up a system of equations to represent this relationship with x= the amount invested at 4% and y = the amount invested at 2.5% How much was invested at 2.5%?

Name the quadrilaterals that have four equal sides.

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

What is the volume of a cone with a height of 6 cm in the radius of 2 cm