how long will it take for my teeth to whiten, if i brush my teeth regularly twice a day?

i have "yellowish" teeth, and id like them to be whitened. how many days/weeks will it take for me to whiten my teeth if i brush them everyday?!
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Strawberries are natural teeth whiteners, simply rub them directly on your teeth or mash into a paste and apply.More remedies and information regarding your teeth at http://useinfo-dentalcare.blogspot.com/
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