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
