You can
put this solution on YOUR website!Apply log rules:
ln(x+2)-ln(4)=-ln x
ln(x+2)-ln(4)+ln x = 0
ln[(x+2)/(4)]+ln x = 0
ln[x(x+2)/(4)] = 0
x(x+2)/(4) = e^0
x(x+2)/(4) = 1
x(x+2) = 4
x^2 + 2x = 4
x^2 + 2x - 4 = 0
Solve using the quadratic equation. Doing so yields:
x = {1.236, -3.236}
.
We can throw out the negative solution, leaving:
x = 1.236
.
Details of quadratic to follow:
| Solved by pluggable solver: SOLVE quadratic equation with variable |
Quadratic equation  (in our case  ) has the following solutons:
For these solutions to exist, the discriminant  should not be a negative number.
First, we need to compute the discriminant :  .
Discriminant d=20 is greater than zero. That means that there are two solutions:  .
Quadratic expression  can be factored:
Again, the answer is: 1.23606797749979, -3.23606797749979.
Here's your graph:
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