Question

3x^2 - 8x +2 =0 solve by corresponding square method

Answers

GPT-4o mini
To solve the quadratic equation \(3x^2 - 8x + 2 = 0\) using the completing the square method, follow these steps:

1. **Divide the entire equation by the coefficient of \(x^2\)** (which is 3 in this case) to make the leading coefficient 1:

\[
x^2 - \frac{8}{3}x + \frac{2}{3} = 0
\]

2. **Rearrange the equation** to isolate the constant on one side:

\[
x^2 - \frac{8}{3}x = -\frac{2}{3}
\]

3. **Complete the square** on the left side. To do this, take half of the coefficient of \(x\) (which is \(-\frac{8}{3}\)), square it, and add it to both sides.

Half of \(-\frac{8}{3}\) is \(-\frac{4}{3}\). Squaring it gives:

\[
\left(-\frac{4}{3}\right)^2 = \frac{16}{9}
\]

Now add \(\frac{16}{9}\) to both sides:

\[
x^2 - \frac{8}{3}x + \frac{16}{9} = -\frac{2}{3} + \frac{16}{9}
\]

To combine the right side, convert \(-\frac{2}{3}\) to a fraction with a denominator of 9:

\[
-\frac{2}{3} = -\frac{6}{9}
\]

Therefore:

\[
-\frac{6}{9} + \frac{16}{9} = \frac{10}{9}
\]

Now we have:

\[
x^2 - \frac{8}{3}x + \frac{16}{9} = \frac{10}{9}
\]

4. **Rewrite the left side as a perfect square**:

\[
\left(x - \frac{4}{3}\right)^2 = \frac{10}{9}
\]

5. **Take the square root of both sides**:

\[
x - \frac{4}{3} = \pm \sqrt{\frac{10}{9}}
\]

This simplifies to:

\[
x - \frac{4}{3} = \pm \frac{\sqrt{10}}{3}
\]

6. **Add \(\frac{4}{3}\) to both sides** to solve for \(x\):

\[
x = \frac{4}{3} \pm \frac{\sqrt{10}}{3}
\]

7. **Simplify** to express the solutions:

\[
x = \frac{4 \pm \sqrt{10}}{3}
\]

Thus, the solutions to the equation \(3x^2 - 8x + 2 = 0\) are:

\[
x = \frac{4 + \sqrt{10}}{3} \quad \text{and} \quad x = \frac{4 - \sqrt{10}}{3}
\]