phan tich da thuc thanh nhan tu
1+x+y+z+xy+yz+zx+xyz
\(\left(x+y+z\right)\left(xy+yz+xz\right)-xyz=xy\left(x+y+z\right)-xyz+\left(yz+xz\right)\left(x+y+z\right)\)
\(=xy\left(x+y+z-z\right)+z\left(x+y\right)\left(x+y+z\right)\)
\(=xy\left(x+y\right)+z\left(x+y\right)\left(x+y+z\right)\)
\(=\left(x+y\right)\left[xy+z\left(x+y+z\right)\right]\)
\(=\left(x+y\right)\left(xy+xz+yz+z^2\right)\)
\(=\left(x+y\right)\left[x\left(y+z\right)+z\left(y+z\right)\right]\)
\(=\left(x+y\right)\left(y+z\right)\left(x+z\right)\)
Phan tich da thuc thanh nhan tu
xy(x+y)+yz(y+z)+zx(x+z)+2xyz
Ta có : \(xy\left(x+y\right)+yz\left(y+z\right)+xz\left(x+z\right)+2xyz\)
\(=\left[xy\left(x+y\right)+xyz\right]+\left[yz\left(y+z\right)+xyz\right]+xz\left(x+z\right)\)
\(=xy\left(x+y+z\right)+yz\left(x+y+z\right)+xz\left(x+z\right)\)
\(=y\left(x+y+z\right)\left(x+z\right)+xz\left(x+z\right)\)
\(=\left(x+z\right)\left(xy+y^2+yz+xz\right)\)
\(=\left(x+z\right)\left(x+y\right)\left(y+z\right)\)
phan tich da thuc thanh nhan tu :xy(x-y)-xz(x+z)+yz(2x+z-y)
Phân tich da thuc thanh nhan tu
a)\(yz\left(y+z\right)+xz\left(z-x\right)-xy\left(x+y\right)\)
\(yz\left(y+z\right)+xz\left(z-x\right)-xy\left(x+y\right)\)
\(=-[xy(x+y)-yz(y+z)-zx(z-x)]\)
\(=-(y.[x(x+y)-z(y+z)]-zx(z-x))\)
\(=-[y.(x^2+xy-zy-z^2)-zx(z-x)]\)
\(=-[y.(x^2-z^2+xy-zy)-zx(z-x)]\)
\(=-(y.[(x+z)(x-z)+y.(x-z)]-zx(z-x))\)
\(=-[y.(x-z)(x+z+y)+zx(x-z)]\)
\(=[(x-z)[y(x+z+y)+zx]]\)
\(=-(x-z)(yx+yz+y2+zx)\)
\(=-(x-z)(yx+zx+yz+y2)\)
\(=-[(x-z)[x.(y+z)+y.(y+z)]]\)
\(=-(x-z)(y+z)(x+y)\)
phan tich da thuc thanh nhan tu (x-y).z^3 +(y-z).x^3 +(z-y).y^3
phan tich da thuc thanh nhan tu
x^2-x-y^2-y
x^2-2xy+y^2-z^2
bai 32 va 33 sbt
lop 8 bai phan tich da thuc thanh nhan tu bang cach nhom hang tu
Ta có
a, x2-x-y2-y
=x2-y2-(x+y)
=(x-y)(x+y) - (x+y)
=(x+y)(x-y-1)
b, x2-2xy+y2-z2
=(x-y)2-z2
=(x-y-z)(x-y+z)
con bai 32, 33 neu ban tra loi duoc minh h them
x^2 - 2xy + y^2 - z^2 phan tich da thuc thanh nhan tur
\(x^2-2xy+y^2-z^2\\=(x^2-2xy+y^2)-z^2\\=(x-y)^2-z^2\\=(x-y-z)(x-y+z)\)
Phan tich da thuc thanh nhan tu
(xy-1)^2 -x^2-y^2
Phan tich da thuc thanh nhan tu: (x+y+z)^5 - x^5 - y^5 - z^5