2×(x-5)-x^2+25=0 Nhanh với ạ

Đáp án:

`2xx(x-5)-x^2+25=0`

⇔`2x-10-x²+25=0`

⇔`-x²+2x+15=0`

⇔`-x²+2x-1+16=0`

⇔`-(x²-2x+1)=-16`

⇔`(x-1)²=16`

⇔\(\left[ \begin{array}{l}x-1=4\\x-1=-4\end{array} \right.\) 

⇔\(\left[ \begin{array}{l}x=5\\x=-3\end{array} \right.\) 

     Vậy `x ∈ {5;-3}`