SOLUTION: multiply (x5+7x)(x5-7x)

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Question 195721: multiply
(x5+7x)(x5-7x)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
%28x%5E5%2B7x%29%28x%5E5-7x%29 Start with the given expression.


Now let's FOIL the expression.


Remember, when you FOIL an expression, you follow this procedure:


%28highlight%28x%5E5%29%2B7x%29%28highlight%28x%5E5%29-7x%29 Multiply the First terms:%28x%5E5%29%2A%28x%5E5%29=x%5E10.


%28highlight%28x%5E5%29%2B7x%29%28x%5E5%2Bhighlight%28-7x%29%29 Multiply the Outer terms:%28x%5E5%29%2A%28-7%2Ax%29=-7%2Ax%5E6.


%28x%5E5%2Bhighlight%287x%29%29%28highlight%28x%5E5%29-7x%29 Multiply the Inner terms:%287%2Ax%29%2A%28x%5E5%29=7%2Ax%5E6.


%28x%5E5%2Bhighlight%287x%29%29%28x%5E5%2Bhighlight%28-7x%29%29 Multiply the Last terms:%287%2Ax%29%2A%28-7%2Ax%29=-49%2Ax%5E2.


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So we have the terms: x%5E10, -7%2Ax%5E6, 7%2Ax%5E6, and -49%2Ax%5E2


x%5E10-7%2Ax%5E6%2B7%2Ax%5E6-49%2Ax%5E2 Now add every term listed above to make a single expression.


x%5E10-49%2Ax%5E2 Now combine like terms.


So %28x%5E5%2B7x%29%28x%5E5-7x%29 FOILs to x%5E10-49%2Ax%5E2.


In other words, %28x%5E5%2B7x%29%28x%5E5-7x%29=x%5E10-49%2Ax%5E2.