\(xy\left(x+y\right)+yz\left(y+z\right)+xz\left(x+z\right)2xyz\)
\(=\left[xy\left(x+y\right)+xyz\right]+\left[yz\left(y+z\right)+xyz\right]+xz\left(x+z\right)\)
\(=xy\left(x+y+z\right)+yz\left(x+y+z\right)+xz\left(x+z\right)\)
\(=\left(xy+yz\right)\left(x+y+z\right)+xz\left(x+z\right)\)
\(=y\left(x+z\right)\left(x+y+z\right)+xz\left(x+z\right)\)
\(=\left(x+z\right)\left[y\left(x+y+z\right)+xz\right]=\left(x+z\right)\left(xy+y^2+yz+xz\right)\)
\(=\left(x+z\right)\left[y\left(x+y\right)+z\left(x+y\right)\right]\)
\(=\left(x+z\right)\left(z+y\right)\left(y+x\right)\)
\(=\left(x+y\right)\left(y+z\right)\left(z+x\right).\)
Phức tạp. Cs cách nào nhanh kkk?
