I need some help on this question please Will give 10 brainlist if you are right

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?

Find the domain and range of the following function f(x) = 51x - 21+ 4

If the tip varies directly with the number of guest which equation represents between the tip,t, and the number of guest,g?