If the letters a, b, c, d, e, and f are to be used in a five-letter code, how many different codes are possible if repetitions are not permitted?

What values of x satisfy the inequality x^2-9x< 0? how is your answer shown on the graph?

Which function has an inverse function? a.f(x)= |x+3|/5 b. f(x)= x^5-3 c. f(x)= x^4/7+27 d. f(x)= 1/x²

Ana earns 2.5% simple interest on $2,000 in her savings account. she does not make any deposits or withdrawals. after 3 years, how much interest will ana have earned on her savings account?