Which expression is equivalent to (81x4y16) for all positive values of x and y?

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?

Ahigh school has 3636 players on the football team. the summary of the players' weights is given in the box plot. approximately, what is the percentage of players weighing less than or equal to 225225 pounds?

How many grams the dog will eat in 3 days?