SOLUTION: Can someone help me solve this for X sqrtx+7 = x+1

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Question 35509: Can someone help me solve this for X
sqrtx+7 = x+1

Found 2 solutions by Nate, rapaljer:
Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
(x+7)^(1/2)=(x+1)
(x+7)=(x+1)^2
x+7=x^2+2x+1
x^2+x-6=0
(x+3)(x-2)=0
x=-3 and x=2
If you plug in the -3, you get 2=-2 .... so -3 isn't an answer.
However, 2 is a right answer, so the answer is x=2.

Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt%28x%2B7%29+=+x%2B1%29+

Square both sides, which eliminates the radical on the left side:
x%2B7+=+%28x%2B1%29%5E2
x%2B7+=+x%5E2+%2B+2x+%2B+1

This is quadratic, so set it equal to zero by subtracting x and 7 from each side.
0+=+x%5E2+%2B2x+%2B1+-+x+-+7
0+=+x%5E2+%2B+x+-+6

It factors!!! (I think they ALWAYS do!!)
+0=+%28x%2B3%29%28x-2%29+
x+=+-3 ++x=+2

HOWEVER, you must check these answers, since you squared both sides of the equation. Substitute both values back into the original equation.

Check x = -3:
sqrt%28x%2B7%29+=+x%2B1%29+
sqrt%28-3%2B7%29+=+-3%2B1
sqrt%284%29+=+-2
This answer must be rejected by the principle value definition of square root.

Check x = 2:
sqrt%28x%2B7%29+=+x%2B1%29+
sqrt%282%2B7%29+=+2%2B1
sqrt%289%29+=+3
This answer checks!!

Final answer is x= 2.

R^2 at SCC