Quadratic Roots F453D0
1. **Problem:** Solve for real $x$ in the quadratic equation $$x^2 - 7x + 10 = 0.$$
2. **Formula:** For a quadratic equation $ax^2 + bx + c = 0$, the roots are given by the quadratic formula:
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}.$$
3. **Apply formula:** Here, $a=1$, $b=-7$, $c=10$. Calculate the discriminant:
$$\Delta = b^2 - 4ac = (-7)^2 - 4 \times 1 \times 10 = 49 - 40 = 9.$$
4. **Find roots:** Since $\Delta > 0$, two distinct real roots exist:
$$x = \frac{-(-7) \pm \sqrt{9}}{2 \times 1} = \frac{7 \pm 3}{2}.$$
5. **Calculate each root:**
- Root 1: $$x = \frac{7 + 3}{2} = \frac{10}{2} = 5.$$
- Root 2: $$x = \frac{7 - 3}{2} = \frac{4}{2} = 2.$$
6. **Answer:** The roots are $x=2$ and $x=5$.
**Correct choice:** A. 2,5