Its a quadratic equation I Dont know exactly how to solve it help please

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

Credit card a offers an introductory apr of 3.4% for the first three months and standard apr of 15.7% thereafter,

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.