Of the positive integers less than 2021, how many can be written as a difference of two powers of 2?

What are the relative frequencies, to the nearest hundredth, of the rows of the two-way table? group 1: a 15 b 45 group 2: a 20 b 25

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

An investment decreases in value by 30% in the first year and decreases by 40% in the second year. what is the percent decrease in percentage in the investment after two years