SOLUTION: Is the following trinomial a perfect square? x2 + 18x + 81

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Question 49473: Is the following trinomial a perfect square?
x2 + 18x + 81
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Is the following a perfect square? x%5E2%2B8x%2B81
Quite likely! Notice that the first term is a perfect square x%5E2+=+%28x%29%5E2 and the last term is a perfect square %289%29%5E2+=+81 and the sum of 9+9 = 18 which is the coefficient of the x-term. So, if you factor the given expression, you'll get:
%28x%2B9%29%28x%2B9%29+=+%28x%2B9%29%5E2 A perfect square!