Multiply & simplify.
2a(7a²-3a+9)

a. 9a³-a²+11a
b. 9a²-a+11
c. 14a²-6a+18
d. 14a³-6a²+18a

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).

1. what is the formula for finding the vertical distance between two points on a coordinate plane?

This is different from the first one can someone me