Question 86907
Given:
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{{{9(x-7)(x+7)/3(x-7)}}}
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The first thing you can do is to divide the 3 in the denominator into the 9 in the numerator.
The result of this division in that you are left with a 3 in the numerator. [You can also
replace the 9 with 3*3 and then cancel the 3 in the denominator with one of the 3s in the
numerator. The result is the same ... a 3 left in the numerator.] The problem is now simplified
to:
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{{{3(x-7)(x+7)/(x-7)}}}
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Next you can cancel the (x-7) in the denominator with the (x-7) in the numerator. 
This cancellation is as follows:
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{{{3(cross(x-7))(x+7)/(cross(x-7))}}}
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And the simplification asked for by the problem is what is now leftover, and is:
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{{{3(x+7)}}}
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If you want to, you can perform the distributed multiplication by 3 to get:
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{{{3x + 21}}}
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Either answer [3(x + 7) or 3x + 21] is correct.
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Hope this helps you to understand the problem.
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