SOLUTION: solve for x log 10^x + log 10^(x-15)=2

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Question 201276This question is from textbook college algebra
: solve for x
log 10^x + log 10^(x-15)=2 This question is from textbook college algebra

Answer by scott8148(6628) About Me  (Show Source):
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taking the antilog ___ x (x-15) = 100

distributing and subtracting 100 ___ x^2 - 15x - 100 = 0

factoring ___ (x - 20) (x + 5) = 0

x - 20 = 0 ___ x = 20

x + 5 = 0 ___ x = -5

since logs are not defined for negative arguments (-5); x = 20