Can someone help me answer part b please .As I have no idea what it is ?

Write a polynomial that fits the description: a third-degree polynomial with leading coefficient -4

What is the measure of x, in degrees

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).