G(x) = 1/3 * (2/9)^x. Does the function model growth or decay?

Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining bismuth-210 transforms into another atom (polonium-210 in this case) each day. if you begin with 233 mg of bismuth-210, how much remains after 8 days?

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle.he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field

Students are getting signatures for a petition to increase sports activities at the community center. the number of signatures they get each day is 3 times as many as the day before. the expression 3^6 represents the number of signatures they got on the sixth day. how many signatures did they get on the first day?