Question 578376
sqrt (x+20) -x=0 
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sqrt(x+20) = x
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Square both sides:
x+20 = x^2
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Rearrange:
x^2 -x - 20 = 0
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Factor:
(x-5)(x+4) = 0
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x = 5 or x = -4
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Check:
Can x = 5 ?
sqrt(5+20)-5 = 0
5 - 5 = 0
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Can x = -4 ?
sqrt(-4+20)-(-4) = 0
sqrt(16) + 4 = 0
4 + 4 = 0
False
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Only solution : x = 5
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Cheers,
Stan H.
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