\(x^2-6xy+9y^2+2\left(x-3y\right)+1=y^2-y+2\)
\(\Leftrightarrow\left(x-3y\right)^2+2\left(x-3y\right)+1=y^2-y+2\)
\(\Leftrightarrow\left(x-3y+1\right)^2=y^2-y+2\)
\(\Leftrightarrow4\left(x-3y+1\right)^2=4y^2-4y+8\)
\(\Leftrightarrow\left(2x-6y+2\right)^2=\left(2y-1\right)^2+7\)
\(\Leftrightarrow\left(2x-6y+2\right)^2-\left(2y-1\right)^2=7\)
\(\Leftrightarrow\left(2x-8y+3\right)\left(2x-4y+1\right)=7\)
Tới đây em tự lập bảng giá trị


