Help PLZZ guys plz i need help on this

For a school newspaper article, cienna conducted a survey to find out students’ favorite subjects. she polled all the students in mrs. lopez’s advanced dance class. why is her data likely to be skewed? honors dance students are more likely to enjoy dance than students in the general population, so dance may be overrepresented. cienna should have interviewed all the students in the school to get more accurate data. honors dance students are more likely to enjoy dance than students in the general population, so dance will be underrepresented. cienna should have interviewed only every other student in the class to avoid having too many people.

Which expression is equivalent to? assume x > 0 and y > 0.

12. the amount of money in a bank account decreased by 21.5% over the last year. if the amount of money at the beginning of the year is represented by ‘n', write 3 equivalent expressions to represent the amount of money in the bank account after the decrease?