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Bansifarms Said:
"I just bought old Mac book OS X but my Apple ID does not work on macbook"
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Is Someone Signed In?
You need to have the person currently sign in to iCloud on it sign out on iCloud. Once they signed out, your need to restart the device, and then sign yourself in. Elsewise, it is useless to you. Go to: System Preferences, and click the name on the top left.
Have the Current Person Use this Site: What to do Before you Sell, Give Away, or Trade in your Mac - Apple Support
Learn from this:
So, contact them, seeing if this can be done. If this is on no option, then take this as a learning experience, knowing to always be allowed to log into it prior to purchasing a used Mac.