To solve the equation \( 7 - x^2 + 2x = 0 \), let's rewrite it in a standard form:
\[ -x^2 + 2x + 7 = 0 \]
Now, let's rearrange it to make the x² term positive:
\[ x^2 - 2x - 7 = 0 \]
Next, we can use the quadratic formula to find the solutions. The quadratic formula is given by:
\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]
Here, \( a = 1 \), \( b = -2 \), and \( c = -7 \).
- Calculate the discriminant \( b^2 - 4ac \):
\[ b^2 - 4ac = (-2)^2 - 4(1)(-7) = 4 + 28 = 32 \]
- Now substitute \( a \), \( b \), and the discriminant into the quadratic formula:
\[ x = \frac{-(-2) \pm \sqrt{32}}{2(1)} = \frac{2 \pm \sqrt{32}}{2} \]
- Simplify \( \sqrt{32} \):
\[ \sqrt{32} = \sqrt{16 \cdot 2} = 4\sqrt{2} \]
Thus:
\[ x = \frac{2 \pm 4\sqrt{2}}{2} = 1 \pm 2\sqrt{2} \]
Now, we have two solutions:
\[ x = 1 + 2\sqrt{2} \quad \text{and} \quad x = 1 - 2\sqrt{2} \]
These are the solutions to the equation \( 7 - x^2 + 2x = 0 \).