### Home > A2C > Chapter 12 > Lesson 12.2.1 > Problem 12-93

12-93.

Prove the relationship is true for *n* = 1.

9 = (1)(2(1) + 7)

9 = 9

Assume that the relationship is true for some number *k*.

Prove that, if the relationship is true for *k*, then it is true for *k* + 1.