In an arithmetic sequence 219 = 1 and a37 = 18. Determine a1.

What is the average rate of change for this function for the interval from x=2 to x=4 ?

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

In a singing competition, there are 150 participants. at the end of each round, 40% of the participants are eliminated. how many participants are left after n rounds?