The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 2\\[1 em]x_2 &= \frac{ 1 }{ 2 } \end{aligned} $$Step 1:
Get rid of fractions by multipling equation by $ \color{blue}{ 2 } $.
$$ \begin{aligned} 1-\frac{5}{2}x+x^2 & = 0 ~~~ / \cdot \color{blue}{ 2 } \\[1 em] 2-5x+2x^2 & = 0 \end{aligned} $$Step 2:
Write polynomial in descending order
$$ \begin{aligned} 2-5x+2x^2 & = 0\\[1 em] 2x^2-5x+2 & = 0 \end{aligned} $$Step 3:
The solutions of $ 2x^2-5x+2 = 0 $ are: $ x = \dfrac{ 1 }{ 2 } ~ \text{and} ~ x = 2$.
You can use step-by-step quadratic equation solver to see a detailed explanation on how to solve this quadratic equation.