SOLUTION: x2 - 64

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Question 590847: x2 - 64
Found 2 solutions by jim_thompson5910, RU5H7777777:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

x%5E2-64 Start with the given expression.


%28x%29%5E2-64 Rewrite x%5E2 as %28x%29%5E2.


%28x%29%5E2-%288%29%5E2 Rewrite 64 as %288%29%5E2.


Notice how we have a difference of squares A%5E2-B%5E2 where in this case A=x and B=8.


So let's use the difference of squares formula A%5E2-B%5E2=%28A%2BB%29%28A-B%29 to factor the expression:


A%5E2-B%5E2=%28A%2BB%29%28A-B%29 Start with the difference of squares formula.


%28x%29%5E2-%288%29%5E2=%28x%2B8%29%28x-8%29 Plug in A=x and B=8.


So this shows us that x%5E2-64 factors to %28x%2B8%29%28x-8%29.


In other words x%5E2-64=%28x%2B8%29%28x-8%29 for all values of x.

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Answer by RU5H7777777(2) About Me  (Show Source):
You can put this solution on YOUR website!
(x-8)(x+8)
=x^2+8x-8x-64
=x^2-64