SOLUTION: Help is needed! square root of 7x+36=x+4

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Question 412302: Help is needed!
square root of 7x+36=x+4
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi,

If I am understanding Your question properly:

sqrt%287x%2B36%29+=+x%2B4   |squaring both sides of the Eq

 7x + 36 = (x+4)^2

 7x + 36 = x^2 + 8x + 16

   x^2 + x - 20 = 0

 (x+5)(x-4)=0 Note:SUM of the inner product(5x) and the outer product(-4x) = x

 (x+5)=0  x = -5  |Extraneous solution sqrt(1) ≠ -1

 (x-4)=0  x = 4