Please help solve equation:
ln x + ln (x + 2) = 4
ln x (x + 2) = 4
e ^ 4 = x (x + 2)
What do I do next to solve for x?
Thank you.
First of all we have to put the conditions for the existence of the logarithms:
$\displaystyle x>0, \ x+2>0\Rightarrow x\in(0,\infty)$.
Now solve the quadratic $\displaystyle x^2+2x-e^4=0$ and choose the right solution which is $\displaystyle x=-1+\sqrt{1+e^4}$