![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Let x be the number of boxes of books.
\The weighs of one box of books is 50 lb.
\The weighs of x boxes of books is 50x lb.
\The weighs of delivery person is 160 lb.
\The maximum capacity of the elevator is 1000 lb.
\Therefore, the above situation represent the equation is ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=50acad03875e64f84c35306f442d299a.png\")
.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
Solve the equation ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=50acad03875e64f84c35306f442d299a.png\")
for x.
Subtract 50 from each side.
\![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=b488ff558932f6cc3a80b548ba9edfad.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a15a1f38be6301ddeb7651d0ec36fa7e.png\")
Divide each side by 50.
\![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8bec474faf5a375796b0bc0cbdb1b9c6.png\")
Cancel common terms.
\![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=90afbdc463da2a1764e572e1302b45f5.png\")
.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The delivery person can bring up 19 boxes of books at one time.