How do you know when there are no solutions to a system of equations? how do you know there are infinity many solutions to a system of equations? how do you know when there is one solution to system of equations?

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

What is the factored form of x2 − 4x − 5? (x + 5)(x − 1) (x + 5)(x + 1) (x − 5)(x − 1) (x − 5)(x + 1)

According to the data set, where should the upper quartile line of the box plot be placed?