ANSWER:
y = x² + 6x +8
Explanation:
The equation in its vertex form has the following form:

We solve for a which is the coefficient of the principal of the equation as follows:

We substitute each value to be able to determine the value of a, like this:

Now we calculate education in its vertex form:

The general form of the equation of the quadratic function is y = x² + 6x +8