Chapter 2 - Solving Linear Inequalities - 2.1 - Writing and Graphing Inequalities - Exercises - Page 59: 37

See image

The equation $x<7$ will represent all numbers less than $7$ excluding $7$. Hence, a hollow mark is made at number $7$ which denotes that $7$ is not included. The numbers to the left are marked with blue. The blue line represents the solution of the inequality $x<7$.