I need to have evidence as well​

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).

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

Consider the function represented by the equation 1/2 j + 1/4 k equals 3 which shows the equation written in function notation with j as the independent variable