Mirella bought some cat food for $2.00 per pound and some dog food for $2.50 per pound. She spent a total of $20.00. Which graph represents all the possible combinations of cat food, c, and dog food, d, Mirella could have bought?

Solve the system of equations. y= 2x y= x^2 - 15

If y varies directly as x2 and y=6 when x=6, find the constant of variation.

Adecibel is a logarithmic unit that can be used to measure the intensity of a sound. the function y = 10logx gives the intensity of a sound in decibels, where x is the ratio of the intensity of the sound to a reference intensity. the reference intensity is generally set at the threshold of hearing. use the graphing utility to graph the decibel function.a whisper has a sound intensity of 30 decibels. use your graph to you complete the following statement. the sound intensity of a whisper is times the reference intensity.