We are given a quadratic equation and its possible solution. The approach taken to solve the equation is to factor the equation and then set both factors to zero. In line (d) we have the following factor:

To solve for "x" we need to subtract 4 from both sides:

Therefore, for this factor, the value of "x" is -4, but in line (e) we see that the given solution is x = 4, therefore, there is an error in that line.