Question 1025087: lg(5x+8) + lg(2x+1) - 2lg(x+1) = 1
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! log(5x+8) + log(2x+1) - 2log(x+1) = 1
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If you want to solve for x:
log(5x+8) + log(2x+1) - 2log(x+1) = log(10)
log((5x+8)*(2x+1)) = 2log(x+1) + log(10) = log(10*(x+1)^2)
(5x+8)*(2x+1) = 10*(x+1)^2 = 10x^2 + 20x + 10
10x^2 + 21x + 8 = 10x^2 + 20x + 10
21x + 8 = 20x + 10
x = 2
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