Giselle works as a carpenter and as a blacksmith. she earns $20 per hour as a carpenter and $ 25 per hour as a blacksmith. last week giselle worked both jobs for a total of 30 hours and earned a total of $690. how long did giselle work as a carpenter last week, and how long did she work as a blacksmith

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.