Question

x²−5x+4=0; допоможіть​

Answer 1

$\displaystyle x^2-5x+4=0\\x^2-4x-x+4=0\\x(x-4)-(x-4)=0\\(x-1)(x-4)=0\\\left[\begin{aligned}&x=1\\&x=4\end{aligned}\right.$

Ответ $\{1,4\}$