Q: Macbook pro Late 2011

The total RAM memory capacity, in chip form, can be upgraded:

•Maximum Memory    16 GB (Actual) 8 GB (Apple)

•Memory Slots    2 - 204-pin PC-10600 (1333 MHz) DDR3 SO-DIMM

•MacBook Pro: How to remove or install memory

You can likely find the memory chips to correctly match your MB/Pro

hardware build model identifier from OWC macsales; or at crucial.com.

http://eshop.macsales.com/shop/memory/Apple_MacBook_MacBook_Pro/Upgrade/DDR3_133 3MHz_SDRAM

There may be some other software running that can account for slow

computer action, such as antivirus software (unnecessary, remove)

or adware, genieo, conduit, or mackeeper, cleanmymac, etc. Junk.

For some ideas on what may be causing additional slow issues:

http://www.thesafemac.com/tech-guides/

So without knowing your use and where you may have gotten any

download software from, be it free or not, the slowness may have

other sources than just the computer lacking RAM.

Could be the hard disk drive is too full of saved files, music libraries

or movies, etc; these can all slow the computer, too.

PS: Also, I notice you asked about same slow MacBook last December:

Slow mac

Good luck & happy computing!

edited

You haven't given us much to go on. No idea what you might be running, how full your hard drive is, what Activity Monitor Memory tab shows for MEMORY PRESSURE, EtreCheck.

If this user's computer is also still running a partition with Windows,

that also adds another avenue of inquiry; w/ limited resources, likely.

Note an earlier thread on this: •Slow mac

Thought I'd point back ^ to a little history, probably unresolved even then...