Chapter 1 - Some Basic Concepts of Arithmetic and Algebra - 1.2 - Prime and Composite Numbers - Problem Set 1.2 - Page 12: 15

False.

$9x = 119$ $x = \frac{119}{9}$ $x = 13.222$ For 9 to be a factor of 119, a whole-number factor, x, needs to be multiplied by $9$ to get $119$. However, this factor, x, is not a whole number, so we know that 9 is not a factor of 119.