Question: Consider the equation $$2x^2+7x+4=8$$.
Find the solutions to the equation by using the quadratic formula.
x = 0.5 and x = 4
x = -4 and x = -0.5
x = -4 and x = 0.5
x = -0.5 and x = 4
1. **State the problem:** Solve the quadratic equation $$2x^2+7x+4=8$$ using the quadratic formula.
2. **Rewrite the equation in standard form:** Move all terms to one side:
$$2x^2 + 7x + 4 - 8 = 0$$
which simplifies to
$$2x^2 + 7x - 4 = 0$$
3. **Recall the quadratic formula:** For an equation $$ax^2 + bx + c = 0$$, the solutions are given by
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
4. **Identify coefficients:** Here, $$a=2$$, $$b=7$$, and $$c=-4$$.
5. **Calculate the discriminant:**
$$\Delta = b^2 - 4ac = 7^2 - 4 \times 2 \times (-4) = 49 + 32 = 81$$
6. **Calculate the square root of the discriminant:**
$$\sqrt{81} = 9$$
7. **Apply the quadratic formula:**
$$x = \frac{-7 \pm 9}{2 \times 2} = \frac{-7 \pm 9}{4}$$
8. **Find the two solutions:**
- For the plus sign:
$$x = \frac{-7 + 9}{4} = \frac{2}{4} = 0.5$$
- For the minus sign:
$$x = \frac{-7 - 9}{4} = \frac{-16}{4} = -4$$
9. **Final answer:** The solutions are $$x = 0.5$$ and $$x = -4$$.
10. **Match with given options:** The correct choice is **x = -4 and x = 0.5**.