how do I delete unwanted pages from an excel sheet

If you explicitly set the Print Area, then choose Print Area/Clear Print Area from the File menu to reset it to the used cells.

If that doesn't reset the Print Area, then you still have content (perhaps space characters, if you used them to "clear" cells?) in your "removed pages" area (rows/columns). Select the rows below your last valid data through the last row printed and choose Edit/Delete. Do the same for 'unused', but still printing, columns to the right of your data.

Were they separate Sheets in a workbook IF so:

1. Control click on tab of unwanted sheet wait for context menu to come up.
2. Choose delete.

a modal window comes up asking if you wish to delete this sheet.

Click okay.

                                                      Control Click⬆

If you don't see the tabs check this:

 My arrow pointer is on top of the top of the item you grab.

Had the same issue.  I found that even merged cells will cause unwanted pages to remain on your sheet even though you have reset your print area and there is no visible data on the pages. 

Select the columns of the unwanted page to the right.

Go to "Merge & Center", from drop down select "Unmerge Cells"

Do this for the pages near the bottom except select all the rows of the unwanted page.

When you change your focus all the unwanted headers, footers & pages should be gone.

Clear and reset your Print Area

Save!