Đáp án:
$x^{2}$ $-$ $2x$ $+$ $1$ $=$ $25$
$<=>$ $(x-1)^{2}$ $=$ $25$
$<=>$ $(x-1)^{2}$ $-$ $25$ $=$ $0$
$<=>$ $(x-1)^{2}$ $-$ $5^{2}$ $=$ $0$
$<=>$ $(x-1-5)$ $.$ $(x-1+5)$ $=$ $0$
$<=>$ \(\left[ \begin{array}{l}x-6=0\\x+4=0\end{array} \right.\)
$<=>$ \(\left[ \begin{array}{l}x=6\\x=-4\end{array} \right.\)
$Vậy$ $pt$ $có$ $nghiệm$ $:$ $S$ $=$ {$-4;6$}
$Chúc$ $bạn$ $học$ $tốt$$!$
$Answered$ $by$ $Mai$ $Chi$$.$
(Tự làm+ko copy bài trên!)
