In order to complete the square, let's identify the coefficient of the variable x, then we need to add and subtract the square of half the coefficient, so we can use the notable product below:
[tex]x^2+kx+(\frac{k}{2})^2=(x+\frac{k}{2})^2[/tex]
The coefficient of x is 14, so we have:
[tex]\begin{gathered} x^2+14x+33=0\\ \\ x^2+14x+(\frac{14}{2})^2-(\frac{14}{2})^2+33=0\\ \\ (x+7)^2-49+33=0\\ \\ (x+7)^2-16=0\\ \\ (x+7)^2=16 \end{gathered}[/tex]
Therefore the value of D is 7 and the value of E is 16.
