SOLUTION: square root of (2x+3) = x I got x = -1, 3 but my answer sheet says only x = 3 WHY?

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Question 449726: square root of (2x+3) = x
I got x = -1, 3 but my answer sheet says only x = 3 WHY?
Answer by Leaf W.(135) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt%282x+%2B+3%29+=+x
You found the solutions correctly, but you must check your answers in all square-root equations like this.
-1 is not an answer because:
sqrt%282%28-1%29+%2B+3%29+=+-1
sqrt%28-2+%2B+3%29+=+-1
sqrt%281%29+=+-1
1+=+-1 <== FALSE!
Sure, if you multiply -1*-1, that equals 1, so technically sqrt%281%29+=+-1 is correct, but in order to avoid confusion, people have decided to denote only a positive number x as sqrt%28x%5E2%29; negative x is denoted as -sqrt%28x%5E2%29. For example:
5 is denoted as sqrt%2825%29
-5 is denoted as -sqrt%2825%29, NOT sqrt%2825%29
Since sqrt%282%283%29+%2B+3%29+=+3
sqrt%286+%2B+3%29+=+3
sqrt%289%29+=+3
3+=+3 is correct,
***The only solution for x is 3.
I hope that makes sense! =)