SOLUTION: multiply - (2x-1)(2x+1)

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Question 77643: multiply -
(2x-1)(2x+1)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
In order to multiply terms in parenthesis, we have to foil the terms. So we multiply the first terms together to get 2x%2A2x=4x%5E2. Then we multiply the outer terms together 2x%2A1=2x and the inner terms -1%2A2x=-2x. Finally we multiply the last terms -1%2A1=1 to finally get

%282x-1%29%282x%2B1%29=2x%2A2x%2B2x%2A1-1%2A2x-1%2A1=4x%5E2%2B2x-2x-1
Now combine like terms
4x%5E2%2Bcross%282x-2x%29-1=4x%5E2-1 Notice the x terms cancel
So %282x-1%29%282x%2B1%29 foils (ie multiplies) to 4x%5E2-1