Exercise 14 Page 197

Before we can write the inequality in set-builder notation, we have to solve the inequality by isolating r.

To use set-builder notation, we need a variable, which in this case is r, and a statement describing the elements of the set. Knowing that r<11 is the solution to the inequality, we can write the solution in set-builder notation. { r | r < 11} This can be read as the set includes any value of r such that r is less than 11.