Mathematics
Gouldman696
2015-10-29 13:33:27
Please help! Solve the logarithmic equation algebraically. ln(x + 9) = ln(x - 6) - ln(x + 6)
ANSWERS
pinmypie
2015-10-29 17:50:11

ln(x + 9) = ln(x - 6) - ln(x + 6) , but: ln(x - 6) - ln(x + 6) = ln[(x-6)/(x+6)], So: If ln(x + 9) = ln[(x-6)/(x+6)], then: (x+9) =  (x-6)/(x+6), Cross multiplication: (x+9)(x+6) = (x-6) →→ x² + 14x + 60 = 0 Solving this quadratic equation gives : x₁ = -7+√11 .i x₂ = -7 -√11 .i

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