How is graphing a two variable inequality similar to graphing a one variable inequality on the number line?

There are several ways that it is similar. 

1) You still shade on the parts that satisfy the inequality (even though it is 2 dimensional instead of 1. 

2) You still need to show whether or not it is "greater than" or "greater than or equal to". On a line graph you use an open or closed dot, on a graph you use a dotted or solid line.