Recycled CDs, Incorporated, offers a choice of 5 used CDs for $, with each additional CD costing $. Write a cost function for purchasing 5 or more CDs. What will the cost of buying CDs be? Let x represent the number of CDs over 5

The probability that a student graduating from suburban state university has student loans to pay off after graduation is .60. if two students are randomly selected from this university, what is the probability that neither of them has student loans to pay off after graduation?

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.