To solve the quadratic equation \(x^2 + 4x + 7 = -1\), we first move all terms to one side to set the equation to zero. This gives us \(x^2 + 4x + 8 = 0\). We can then use the quadratic formula \(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\) to find the roots of the equation, where \(a = 1\), \(b = 4\), and \(c = 8\).
Step 1: Set the Equation to Zero
We start with the equation:
\[
x^2 + 4x + 7 = -1
\]
By moving \(-1\) to the left side, we rewrite the equation as:
\[
x^2 + 4x + 8 = 0
\]
Step 2: Calculate the Discriminant
The discriminant \(D\) of a quadratic equation \(ax^2 + bx + c = 0\) is given by:
\[
D = b^2 - 4ac
\]
Substituting \(a = 1\), \(b = 4\), and \(c = 8\):
\[
D = 4^2 - 4 \cdot 1 \cdot 8 = 16 - 32 = -16
\]
Since the discriminant is negative, the solutions will be complex.
Step 3: Find the Roots
Using the quadratic formula:
\[
x = \frac{-b \pm \sqrt{D}}{2a}
\]
Substituting \(D = -16\):
\[
x = \frac{-4 \pm \sqrt{-16}}{2 \cdot 1} = \frac{-4 \pm 4i}{2} = -2 \pm 2i
\]
Thus, the two solutions are:
\[
x_1 = -2 + 2i \quad \text{and} \quad x_2 = -2 - 2i
\]
Final Answer
The solutions to the equation \(x^2 + 4x + 7 = -1\) are:
\[
\boxed{x = -2 + 2i} \quad \text{and} \quad \boxed{x = -2 - 2i}
\]