SOLUTION: I need help solving and check for extraneous solutions: √y+9=1

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Question 111663: I need help solving and check for extraneous solutions:
√y+9=1
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve and check for extraneous roots.
sqrt%28y%2B9%29+=+1 Square both sides. This might introduce extraneous roots.
y%2B9+=+1 or y%2B9+=+-1 Subtract 9 from both sides in both of these.
y+=+-8 or y+=+-10
Check solutions:
sqrt%28y%2B9%29+=+1 Substitute y = -8.
sqrt%28-8%2B9%29+=+1
sqrt%281%29+=+1 Ok
sqrt%28y%2B9%29+=+1 Substitute y = -10
sqrt%28-10%2B9%29+=+1
sqrt%28-1%29+=+1 Not valid! This is an extraneous root.