证明方程x^4+y^4+Z^4=2x^2y^2+2y^2z^2+2z^2X^2+40无整数解
设x、y、z为整数,证明:x^4*(y-z)+y^4*(z-x)+z^4*(x-y)/(y+z)^2+(z+x)^2+(
x,y,z正整数 x>y>z证明 x^2x +y^2y+z^2z>x^(y+z)*y^(x+z)*z^(x+y)
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
解方程:{2x+3y+z=7,x+y+z=4,3x+y-z=-4
解方程{3x -y+z=4 2x+3y-z=12 x+y+z=6
证明题:证明当n是一个整数且n>2时,方程x^n+y^n=z^n无正整数x,y,z的解.
(y-x)/(x+z-2y)(x+y-2z)+(z-y)(x-y)/(x+y-2z)(y+z-2x)+(x-z)(y-z
已知 x,y,z都是正实数,且 x+y+z=xyz 证明 (y+x)/z+(y+z)/x+(z+x)/y≥2(1/x+1
证明当n是一个整数且n>2时,方程x^n+y^n=z^n无正整数x,y,z的解.
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y
已知(x+y+z)^2=x^2+y^2+z^2,证明x(y+z)+y(z+x)+z(x+y)=0