\(\left(x+y+z\right)\left(x-y+z\right)=\left(x+z+y\right)\left(x+z-y\right)\)
\(=\left(x+z\right)^2-y^2\)
\(\left(x+y+z\right)\left(x-y+z\right)=\left(x+z+y\right)\left(x+z-y\right)\)
\(=\left(x+z\right)^2-y^2\)
giai he phuong trinh
x+y+z=2016
(x*y/x*x+x*y+y*y)+(y*z/y*y+y*z+z*z)+(z*x/z*z+z*x+x*x)=1
Chứng minh rằng:
(y-z)/(x-y)(x-z) + (z-x)/(y-z)(y-x) + (x-y)/(z-x)(z-y) = 2/(x-y) + 2/(y-z) + 2/(z-x)
Chứng minh rằng:
(y-z)/(x-y)(x-z) + (z-x)/(y-z)(y-x) + (x-y)/(z-x)(z-y) = 2/(x-y) + 2/(y-z) + 2/(z-x)
Cho 1/x+y +1/y+z +1/z+x=0 Tính P=(y+z)(z+x)/(x+y)^2 + (x+y)(z+x)/(y+z)^2+ (y+z)(x+y)/(z+x)^2
Bài1: Cho x+y+z=0; xyz(x-y)(y-z)(z-x)#0. CMR: A=(x-y/z + y-z/x + z-x/y)(z/x-y + x/y-z + y/z-x) có giá trị ko đổi
Bài 2: CMR nếu x+y+z=m; 1/x +1/y +1/z=m thì (x-m)(y-m)(z-m)=0
Cho (y-z)/((x-y)*(x-z))+(x-z)/((y-x)*(y-z))+(x-y)/((z-x)*(z-y)) biết x=759, y=742, z=850
Cho x+y+z=0
Tính P= (x-y/z + y-z/x + z-x/y)(z/x-y + x/y-z + y/z-x)
CHO x,y,z khác 0 và (x-y-z)/x = (y-z-x)/y = (z-y-x)/z.
Tính (1+y/x)(1+z/y)(1+x/z)
Cộng các phân thức
a ) 1/( x-y)(y-z) + 1/ ( y-z)(z-x) + 1/ (z-x)(x-y) b ) 4/(y-x)(z-x) + 3/(y-x)(y-z)+ 3/(y-x)(x-z)
Phân tích đa thức thành nhân tử
d (a² + a)² + 4(a² + a) - 12
e) (x² + x + 1)( x² + x + 2) -12
g) x⁸ + x + 1 h) x¹⁰ + x⁵ + 1
i) x³ ( z -y² ) + y³ ( x - z² ) + z³ ( y - x² ) + xyz( xyz - 1 )
k) x(y - z)² + y(z - x)² + z(x - y)² - x³ - y³ - z³ + 4xyz
l) (x + y + z)³ - (x + y - z)³ - (y + z - x)³ - (z + x - y)³