Question

Phân tích đa thức thành nhân tử

Answer 1

\(k,\\ =\left(x-y\right)^2-9z^2=\left(x-y-3z\right)\left(x-y+3z\right)\\ l,\\ =a^3\left(a-x\right)-y\left(a-x\right)\\ =\left(a^3-y\right)\left(a-x\right)\\ m,\\ =2x^2\left(y+2z\right)+2y^2z+4xy^2+2xz^2+4yz^2+9xyz\\ =2x^2\left(y+2z\right)+\left(2y^2z+4yz^2\right)+\left(4xy^2+8xyz\right)+\left(xyz+2xz^2\right)\\ =2x^2\left(y+2z\right)+2yz\left(y+2z\right)+4xy\left(y+2z\right)+xz\left(y+2z\right)\\ =\left(2x^2+2yz+4xy+xz\right)\left(y+2z\right)\\ =\left[x\left(2x+z\right)+2y\left(z+2x\right)\right]\left(y+2z\right)\\ =\left(2y+x\right)\left(2x+z\right)\left(y+2z\right)\)