Câu 1:
c: \(x^3-3x^2-4x+12\)
\(=x^2\left(x-3\right)-4\left(x-3\right)\)
\(=\left(x-3\right)\left(x-2\right)\left(x+2\right)\)
Câu 1:
\(a,=3x\left(3xy-5y^2-1\right)\\ b,=\left(x+2y\right)^2-4z^2=\left(x+2y-2z\right)\left(x+2y+2z\right)\\ c,=\left(x-3\right)\left(x^2-4\right)=\left(x-2\right)\left(x+2\right)\left(x-3\right)\)
Câu 2:
\(a,\Leftrightarrow3x^2-6x+3+2x-3x^2+10-15x=-25\\ \Leftrightarrow-19x=-38\Leftrightarrow x=2\\ b,\Leftrightarrow\left(x-2\right)\left(x-2-4\right)=0\Leftrightarrow\left[{}\begin{matrix}x=2\\x=6\end{matrix}\right.\\ c,\Leftrightarrow\left(x+8\right)\left(x-1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-8\\x=1\end{matrix}\right.\)
Câu 3:
\(a,=x^2+2x-2x=x^2\\ b,=4-x^2+x^2=4\\ c,=x^2-x^3+x^3+27=x^2+27\)
