![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Let c is the number of CDs and d is the number of DVDs.
\The cost of one CD is 10 dollars and the cost of one DVD is 13 dollars.
\The cost of c CDs is 10c dollars and the cost of d DVDs is 13d dollars.
\The total cost spent on these items is 40 dollars.
\Therefore, this situation represent the inequality ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=bec97416ac00c20eebb2c497a5908ec5.png\")
. ![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The inequality is .