Kiersten runs a website that helps people learn programming. Every month, Kiersten receives a subscription fee of $10 from each of the subscribers to her website. Last month, the website had 100 subscribers. This month, 30 new members joined the website, and 10 members cancelled their subscription.
How much money will Kiersten’s online business earn this month?

Me because some of question i don’t understand

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)

The means and mean absolute deviations of the individual times of members on two 4x400-meter relay track teams are shown in the table below. means and mean absolute deviations of individual times of members of 4x400-meter relay track teams team a team b mean 59.32 s 59.1 s mean absolute deviation 1.5 s 245 what percent of team b's mean absolute deviation is the difference in the means? 9% 15% 25% 65%