1. **State the problem:** Solve the quadratic equation $$t^2 - 4t - 40 = 0$$ for $t$.
2. **Recall the quadratic formula:** For an equation $$ax^2 + bx + c = 0$$, the solutions are given by
$$t = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $a=1$, $b=-4$, and $c=-40$.
3. **Calculate the discriminant:**
$$\Delta = b^2 - 4ac = (-4)^2 - 4 \times 1 \times (-40) = 16 + 160 = 176$$
4. **Apply the quadratic formula:**
$$t = \frac{-(-4) \pm \sqrt{176}}{2 \times 1} = \frac{4 \pm \sqrt{176}}{2}$$
5. **Simplify the square root:**
$$\sqrt{176} = \sqrt{16 \times 11} = 4\sqrt{11}$$
6. **Substitute back:**
$$t = \frac{4 \pm 4\sqrt{11}}{2}$$
7. **Simplify the fraction by canceling common factor 2:**
$$t = \frac{\cancel{2} \times 2 \pm \cancel{2} \times 2\sqrt{11}}{\cancel{2} \times 1} = 2 \pm 2\sqrt{11}$$
8. **Final solutions:**
$$t = 2 + 2\sqrt{11} \quad \text{or} \quad t = 2 - 2\sqrt{11}$$
Quadratic Solve 82D649
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