Factor 9x^2 -5 . using difference of squares

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).

Write the pair of fractions as a pair of fractions with a common denominator

Which is the solution to the inequality? 2 3/52 1/15 b< 3 2/15 b> 3 2/15