Giải:
\(4x\left(x-3\right)-\left(2x-5\right)^2=-1\)
\(\Leftrightarrow4x^2-12x-\left(4x^2-20x+25\right)=-1\)
\(\Leftrightarrow4x^2-12x-4x^2+20x-25=-1\)
\(\Leftrightarrow8x-25=-1\)
\(\Leftrightarrow8x=-1+25\)
\(\Leftrightarrow8x=24\)
\(\Leftrightarrow x=\dfrac{24}{8}\)
\(\Leftrightarrow x=3\)
Vậy \(x=3\).
Chúc bạn học tốt!!!
\(4x\left(x-3\right)-\left(2x-5\right)^2=-1\)
\(\Leftrightarrow4x^2-12x-\left(4x^2-20x+25\right)=-1\)
\(\Leftrightarrow4x^2-12x-4x^2+20x-25+1=0\)
\(\Leftrightarrow8x-24=0\Leftrightarrow8x=24\Leftrightarrow x=\dfrac{24}{8}=3\) vậy \(x=3\)
