(2) The viewer may not understand the concept if certain things go unnoticed. One of these things is that the viewer must be careful to complete the square correctly otherwise the rest of the information of the problem will be wrong. Additionally, the viewer must pay attention to the numbers meticulously because there is quite some work to do and simple mistakes can cause incorrect answers.
Step 1 includes completing the square. The first picture shows this step. We started with 2x^2 + 12x +6 = 0 and we ended up with 2(x + 3)^2 = 5.