In 2008, the population of Earth reached 6,690,000,000. How would you represent this number in Scientific Notation?

Use set builder notation to represent the following set: { -3, -2, -1, 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?

Just tell me how to set up the equation.