SOLUTION: solve by completing the square. a^2-2a-8=0??

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Question 284251: solve by completing the square. a^2-2a-8=0??
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
a%5E2+-2a+%2B+1+=+8%2B1
.
%28a-1%29%28a-1%29+=+9
.
%28a-1%29%5E2+=+9
.
a-1+=+sqrt%289%29+=+3
.
a+=+3+%2B+1+=+4
.
Checking...
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%284%5E2%29+-2%284%29+-8+=+0??
16+-+8+-8+=+0
Correct.
.
Answer: a=4
.
Done