<PRE><B>Question 475897</B>
If a number is subtracted from 13, the principal square of this difference is equal to the number decreased by 1.
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(13-x)^2 = x-1
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169 -26x+x^2 = x-1
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x^2 -27x +170 = 0
(x-10)(x-17) = 0
x = 10 or x = 17
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Cheers,
Stan H.
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