\(A=x^2-2xy+y^2+x^2+2xy+y^2+x^2-y^2=3x^2+y^2\\ B=\left(x-y-x+y-z\right)^2=\left(-z\right)^2=z^2\)
\(A=x^2-2xy+y^2+x^2+2xy+y^2+x^2-y^2=3x^2+y^2\\ B=\left(x-y-x+y-z\right)^2=\left(-z\right)^2=z^2\)
Rút gọn biểu thức :
a) \(\left(x+y\right)^2+\left(x-y\right)^2\)
b) \(2\left(x-y\right)\left(x+y\right)+\left(x+y\right)^2+\left(x-y\right)^2\)
c) \(\left(x-y+z\right)^2+\left(z-y\right)^2+2\left(x-y+z\right)\left(y-z\right)\)
rút gọn biểu thức :
a,[x+y]^2.[x-y]^2
b,2.[x-y][x+y]+[x+y]^2+[x-y]^2
c,[x-y+z]^2+[z-y]^2+2.[x-y+z][y-z]
Bài 1: Rút gọn:
a,(x+y)\(^2\)+(x-y)\(^2\)
b, 2(x-y)(x+y)+(x+y)\(^2\)+(x-y)\(^2\)
c,(x-y+z)\(^2\)+(z-y)\(^2\)+2(x-y+z)(y-z)
Chứng minh đẳng thức
a, (x-y-z)^2=x^2 + y^2+z^2-2xy+2yz-2zx
b, ( x+y-z)^2=x^2+y^2+z^2+2xy-2yz-2zx
c, ( x-y)(x^3+x^2y+xy^2+y^3)=5x(x+1)
d, ( x+y)(x^4-x^3y+x^2y^2-xy^3+y^4)=x^5+y^5
Giúp mk vs ạ mk đang cần
rút gọn biểu thức
a) \(\left(x+y\right)^2+\left(x-y\right)^2\)
b) 2 ( x - y ) ( x + y ) + \(\left(x+y\right)^2+\left(x-y\right)^2\)
c)\(\left(x-y+z\right)^2-\left(z-y\right)^2+2\left(x-y+z\right)\left(y-z\right)\)
Cho x,y,z khác 0 và x+y+z=0 . Tính:
A=\(\dfrac{x^2}{y^2+z^2-x^2}+\dfrac{y^2}{z^2+x^2-y^2}+\dfrac{z^2}{x^2+y^2-z^2}\)
Rút gọn biểu thức:
a,A=(x - y + z)2 + ( z - y )2 + 2(x - y + z)(y - z)
b,B=(5x -1) + 2(1-5x)(4 + 5x) + ( 5x + 4)2
c,C=(x - y )3 + ( y+ x)3 + ( y - x)3 - 3xy( x + y)
A [X-2]3 -X [X+1] [X-1] + 6X [X-3]
B [X-2] [X2 - 2X + 4] [X+2] [X2 + 2X + 4]
C [2X+Y] [4X2 - 2XY + Y2 ] - [2X -Y ] [4X2 + 2XY + Y2 ]
D [X + Y ]3 - [X-Y]3 - 2Y3
E [ X+ Y +Z]2 -2 [X +Y+Z] [X+Y] + [X+Y]
(x-y+x)2 + (z-y)2 + 2(x-y+z)(y+z)