the function Q(t)=Q0 e^-kt may be used to model radioactive decay. q represents the quantity remaining after t years. k is the decay constant, 0.00011. how long, in years, will it take for a quantity of plutonium-240 to decay 25% of its original amount

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

Solve x+3y=6 and 4x-6y=6 by elimination . show work !

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.