Phân tích đa thức thành nhân tử
a) x2+2xy-8y2+2xz+14yz-3z2
b) 3x2-22xy-4x+8y+7y2+1
c) 12x2-5x-12y2-12y-10xy-3
d) 2x2-7xy+3y2+5xz-5yz+2z2
e) x2+3xy+2y2-3xz-5yz+2z2
f) x2-8xy+15y2+2x-4y-3
g) x4-13x2+36
i) x4+3x2-2x+3
k) x4+2x3+3x2+2x+1
g: \(=x^4+12x^2+36-25x^2\)
\(=\left(x^2+6\right)^2-25x^2\)
\(=\left(x^2+5x+6\right)\left(x^2-5x+6\right)\)
\(=\left(x-2\right)\left(x-3\right)\left(x+2\right)\left(x+3\right)\)
i: \(x^4+3x^2-2x+3\)
\(=x^4-x^3+x^2+x^3-x^2+x+3x^2-3x+3\)
\(=\left(x^2-x+1\right)\left(x^2+x+3\right)\)