![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
Select two different rational numbers and then determine whether
\the subtraction is a rational number.
\ \Try some examples.
\![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0f66d11235c78a4c112ec8934d98d2b9.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=6323f88bf62a72ee5d06a09a3ef26243.png\")
Since the subtraction of each pair of rational numbers is rational numbers, the set
\of rational numbers is closed under subtraction. ![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
The set of rational numbers is closed under subtraction.