lily bought a cellular phone that was reduced from R399 to R319. If she gives the cashier four hundred rand notes what change will she receive ?​

Need on this geometry question. explain how you did it.

The square root of 9x plus 7 plus the square rot of 2x equall to 7

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.