How do you solve #log(x)+log(x+1)=log(12)#?
The answer is
You first have to say where the equation is defined : it is defined if
Now that this is clear, you now have to use the fact that natural logarithm maps addition into multiplication, hence this :
You can now use the exponential function to get rid of the logarithms :
You develop the polynomial at the left, you substract 12 at both sides, and you now have to solve a quadratic equation :
You now have to calculate