Me! and explain how to solve this. especially questions b, c, and e

Autility company burns coal to generate electricity. the cost c(p), (in dollars) of removing p percent of the some stack pollutants is given by c(p)= 85000p/100-p a) find the cost to remove 30% of the pollutant b) find where the function is undefined

For what values of b will f(x)= logbx be a decreasing function? (16 )

In 1995 america online had about 3000000 users over the next decade users are expected to increase from a few million to the tens of millions suppose the number of users increased by 150% by the year 2000 how many users will there be in the year 2000