![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
\
The expression is ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=72106c4dc3ea25f27c3fa004a9589e0b.png\")
. Radicand is 16.
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=cdce6b41ca49d0797be7216585b2b938.png\")
(The negative square root of radicand: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=f5dd66df208f2f2883dff3ff51c9d84d.png\")
)
§ Observe the Venn diagram:
\§ The number 4 is a positive integer number (Z).
\§ The sets of integers (Z) are subsets of rational number (Q).
\§ All rational numbers (Q) are real numbers (R).
\![\"\"](\"/userfiles/image/realnumber.jpg\")
\ \
![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
The number ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=72106c4dc3ea25f27c3fa004a9589e0b.png\")
belongs to Z, Q and R.