1. **State the problem:** Solve the quadratic equation $$5r^2 + r - 2 = 0$$ for all real values of $r$.
2. **Recall the quadratic formula:** For an equation $$ax^2 + bx + c = 0$$, the solutions are given by
$$r = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $a=5$, $b=1$, and $c=-2$.
3. **Calculate the discriminant:**
$$\Delta = b^2 - 4ac = 1^2 - 4 \times 5 \times (-2) = 1 + 40 = 41$$
Since $\Delta > 0$, there are two distinct real solutions.
4. **Apply the quadratic formula:**
$$r = \frac{-1 \pm \sqrt{41}}{2 \times 5} = \frac{-1 \pm \sqrt{41}}{10}$$
5. **Final answer:**
The solutions in simplest form are
$$r = \frac{-1 + \sqrt{41}}{10} \quad \text{and} \quad r = \frac{-1 - \sqrt{41}}{10}$$
Quadratic Equation 19Dedc
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