hi. i cant remember my security questions answers so i cant not buy anything in itunes or app store . how can i get the aswers or change them ?

Didn't the link to contact the iTunes Store staff in the 'Additional Information' section of that article work for you? If you didn't previously set up a rescue email address, only Apple itself can assist with recovering lost answers.

(87953)

Apple ID Security -

Telephone Apple Care for your country and ask for the Account Security Team, then request help resetting the questions.

Or use this link for contact by internet-

http://www.apple.com/support/appleid/contact/

Choose Other Apple ID Topics and then Apple ID Account Security