Question 804824
logx+log(x+21)=2
{{{log(x*(x+21)) = 2}}}
{{{x*(x+21) = 100}}}
{{{x^2 + 21x - 100 = 0}}}
(x+25)*(x-4) = 0
x = 4

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You can't use x = -25, log(-25) is not allowed