Question 290 of 480
What are the solutions to the quadratic equation \(2x^2 - 8x + 6 = 0\)?
- \(x = 1\) and \(x = 3\)
- \(x = 2\) and \(x = 3\)
- \(x = 1\) and \(x = 4\)
- \(x = 3\) and \(x = 2\)
Correct Answer:
A
Explanation
To solve the quadratic equation \(2x^2 - 8x + 6 = 0\), we will use the quadratic formula, which is given by:
\[
x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
\]
where \(a\), \(b\), and \(c\) are the coefficients from the quadratic equation in the standard form \(ax^2 + bx + c = 0\).
### Step 1: Identify the coefficients
From the equation \(2x^2 - 8x + 6 = 0\), we can identify:
- \(a = 2\)
- \(b = -8\)
- \(c = 6\)
### Step 2: Calculate the discriminant
The discriminant \(D\) is calculated using the formula:
\[
D = b^2 - 4ac
\]
Substituting the values of \(a\), \(b\), and \(c\):
\[
D = (-8)^2 - 4 \cdot 2 \cdot 6
\]
\[
D = 64 - 48
\]
\[
D = 16
\]
### Step 3: Apply the quadratic formula
Now that we have the discriminant, we can substitute \(a\), \(b\), and \(D\) into the quadratic formula:
\[
x = \frac{-(-8) \pm \sqrt{16}}{2 \cdot 2}
\]
\[
x = \frac{8 \pm 4}{4}
\]
### Step 4: Calculate the two possible solutions
Now we will calculate the two possible values for \(x\):
1. **First solution**:
\[
x_1 = \frac{8 + 4}{4} = \frac{12}{4} = 3
\]
2. **Second solution**:
\[
x_2 = \frac{8 - 4}{4} = \frac{4}{4} = 1
\]
### Final Solutions
Thus, the solutions to the quadratic equation \(2x^2 - 8x + 6 = 0\) are:
- \(x = 3\)
- \(x = 1\)
### Correct Option
The correct option is **A. \(x = 1\) and \(x = 3\)**.
### Explanation of Other Options
- **Option B: \(x = 2\) and \(x = 3\)**: This option is incorrect because \(x = 2\) is not a solution derived from our calculations.
- **Option C: \(x = 1\) and \(x = 4\)**: This option is incorrect because \(x = 4\) is not a solution; we found \(x = 3\) instead.
- **Option D: \(x = 3\) and \(x = 2\)**: This option is incorrect because, while \(x = 3\) is correct, \(x = 2\) is not a solution.
### Common Pitfalls
- **Miscalculating the discriminant**: Always double-check your calculations for \(D\).
- **Forgetting to apply the \(\pm\) in the quadratic formula**: This is crucial as it leads to two distinct solutions.
- **Confusing the order of solutions**: The order of solutions does not matter, but ensure both solutions are correct.
### Revision Summary
- Use the quadratic formula \(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\) to find solutions.
- Calculate the discriminant \(D = b^2 - 4ac\) to determine the nature of the roots.
- Substitute values carefully and remember to consider both \(+\) and \(-\) in the formula.
- Verify your solutions by substituting them back into the original equation.