x4+2x3+x2+1+2(x+x2)
1+2x4-(x2+2x3)
X1+2X2-X3+X4=1
分解因式:-27x3+8 ,(x2-5x+2)(x2-5x+4)-24 ,x5+x4+x3+x2+x1+1
1 总体X~N(2,4),X1,X2,X3,X4为样本,则(X1+X2+X3+X4)/4~( )
1分解因式:2x4-x3-13x2-15=?2.分解因式:x5+x4+x3+x2+x+1=?3分解因式:x4-4x2+6
用列主元Gauss消元法解线性方程组{-x2-x3+x4=0,x1-x2+x3-3x4=1,2x1-2x2-4x3+6x
求线性方程组 x2-x3-x4=0 x1+x2-x3+3x4=1 x1-x2+x3+5x4=-1 x1+2x2-2x3+
已知x2+x+1=0,求x4+2x3-x2-2x+2014
3-X2+X-1分之X4+X3-2乘以x3+2x2+2x+2分之X四次方-1除以-2分之X3-X-X2+1化简
X5-X4+X3+X2+X+1因式分解
x5-x4+x3-x2+x-1因式分解
当b≠?时,方程组 方程组X1+X2+X3+X4=0X2+2X3+2X4=1-X2-2X3-2X4=b3X1+2X2+X