SOLUTION: (x+9)^2

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Question 557541: (x+9)^2
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

%28x%2B9%29%5E2 Start with the given expression.


%28x%2B9%29%28x%2B9%29 Expand. Remember something like x%5E2=x%2Ax.


Now let's FOIL the expression.


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


%28highlight%28x%29%2B9%29%28highlight%28x%29%2B9%29 Multiply the First terms:%28x%29%2A%28x%29=x%5E2.


%28highlight%28x%29%2B9%29%28x%2Bhighlight%289%29%29 Multiply the Outer terms:%28x%29%2A%289%29=9%2Ax.


%28x%2Bhighlight%289%29%29%28highlight%28x%29%2B9%29 Multiply the Inner terms:%289%29%2A%28x%29=9%2Ax.


%28x%2Bhighlight%289%29%29%28x%2Bhighlight%289%29%29 Multiply the Last terms:%289%29%2A%289%29=81.


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So we have the terms: x%5E2, 9%2Ax, 9%2Ax, 81


x%5E2%2B9%2Ax%2B9%2Ax%2B81 Now add every term listed above to make a single expression.


x%5E2%2B18x%2B81 Now combine like terms.


So %28x%2B9%29%5E2 FOILs to x%5E2%2B18x%2B81.


In other words, %28x%2B9%29%5E2=x%5E2%2B18x%2B81.