已知x1,x2,x3,x4为实数,且x1+x2+x3+x4=6,x1^2+x2^2+x3^2+x4^2=12,求证:0=

已知y=4.26X1-2(X2+X3+X4) 且X2>X1 X3>X1 X4>X1 X1+X2+X3+X4=M 求M最小 X1+2X2-X3+X4=1 求线性方程组 x2-x3-x4=0 x1+x2-x3+3x4=1 x1-x2+x3+5x4=-1 x1+2x2-2x3+ 求齐次线性方程组{X1+X2+3X3+2X4=0 2X1+3X2+X3-X4=0 5X1+6X2+10X3+5X4=0} 解线性方程组 求齐次线性方程组X1+X2+X3+X4=0,2X1+3X2-X3-2X4=0,5X1+6X2+2X3+X4 设x1>=x2>=x3>=x4>=2,x2+x3+x4>=x1,求证：（x1+x2+x3+x4）^2 简单线代题///X1+X2+X3+X4+X5=13X1+2X2+X3+X4+3X5=0 X2+2X3+2X4+6X5=3 求线性方程组{X1+X2+2X3-3X4=0; X1+2X2-X3+2X4=0; 2X1+3X2+X3-X4=0}的基础 求线性方程组一般解,2X1+X2-2X3+3X4=03X1+2X2-X3+2X4=0X1+X2+X3-X4=0 设齐次线性方程组:x1+x2+x3+x4=0,x2-x3+2x4=0,2x1+3x2+(a+2)x3+4x4=0,3x1 线性方程组怎么解?x1+x2+2x3-x4=02x1+x2+x3-x4=02x1+2x2+x3+2x4=0 用初等行变换方法求下列线性方程组 x1-x2+x3-x4=1 x1-x2-x3+x4=0 x1-x2-2x3+2x4=-