Square root of negative 81

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).

Complete the statements about the system of linear equation respresented by the tables the equation respented the left table is

What is the ratio of the length of an object in yards to the length of the same object in miles?