can someone please help me out with this, but when you answer please explain how you got your answer because I forgot the steps on how to solve it ​

Which represents the solution set of the inequality 5x-9 < 21? a. x < 12/5 b. x > 12/5 c. x > 6 d. x < 6

Let f(x) = 3 − x . find the average rate of change of f(x) from x = a to x = a + h and simplify your answer so that no single factor of h is left in the denominator.

Which numbers have the same absolute value? choose all that apply. asap will mark at brainliest