If x² - 3x + 2 = 0, values of x correct to one decimal place are :

1. 2.0 and 1.0

2. 2.0 or 1.0

3. 3.0 and 2.0

4. 3.0 or 2.0

Comparing equation x² - 3x + 2 = 0 with ax² + bx + c = 0, we get :

a = 1, b = -3 and c = 2.

By formula,

x = $\dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

Substituting values we get :

$x = \dfrac{-(-3) \pm \sqrt{(-3)^2 - 4 \times 1 \times 2}}{2 \times 1} \\[1em] = \dfrac{3 \pm \sqrt{9 - 8}}{2} \\[1em] = \dfrac{3 \pm \sqrt{1}}{2} \\[1em] = \dfrac{3 \pm 1}{2} \\[1em] = \dfrac{3 + 1}{2} \text{ or } \dfrac{3 - 1}{2} \\[1em] = \dfrac{4}{2} \text{ or } \dfrac{2}{2} \\[1em] = 2.0 \text{ or } 1.0$

Hence, Option 2 is the correct option.