Who want's to do my homework? :D Also this might get deleted cause is out to get me D: Simplify the following rational expression. Use absolute value symbols when needed.

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)

What is the standard form of -5x^2+2x^4-11+x^3+3x