When you delete a partition it just becomes unpartitioned space. Depending on your partition setup you may be able to then extend the existing partition, thereby using up that free space. Without knowing specifics of your partitions it's impossible to tell.
Screenshot of what happens when you delete a partition:
Before = https://copy.com/wOy2HMKOffcz
After = https://copy.com/kDOl7RX0yJPx
Steps:
Step #1
In terminal type sudo apt-get install gparted
. [This is a partitioning program. You can use whatever program you want.]
Step #2
Open Gparted and choose the storage device you wish to modify partitions on. [It's in a list at the top right. If you only have 1 storage device then it will be selected by default.]
Step #3
Right click on the partition you wish to delete, choose delete, and click apply. [Apply is the check mark at the top of the program.]
Step #4
Right click on the partition you wish to extend, choose resize, input the size you want, and click apply. [Apply is the check mark at the top of the program.]
Notes:
-If Ubuntu is running off the partition you wish to adjust the size of, you will be able to extend it, but you won't be able to shrink it. If you need to shrink it you can always boot up and Ubuntu livecd and do the partitioning using it.
-Never move a partition containing an OS. If you shrink a partition from the left to the right that counts as moving because you've changed the starting point.