\(\left(x-2\right)^2-x\left(3+x\right)=25\)
\(\Leftrightarrow\left(x^2-4x+4\right)-\left(3x+x^2\right)=25\)
\(\Leftrightarrow x^2-4x+4-3x-x^2=25\)
\(\Leftrightarrow-7x+4=25\)
\(\Leftrightarrow-7x=25-4\)
\(\Leftrightarrow-7x=21\)
\(\Leftrightarrow x=\dfrac{21}{-7}\)
\(\Leftrightarrow x=-3\)
Vậy: ....