1x2÷1＋2x3÷1＋3x4÷1＋4x5÷1＋5x6÷1.＋n(n＋1）÷1

因式分解：x4+x3+2x2 +x+1 求非齐次线性方程组X1-X2-X3+X4=0,X1－X2＋X3－3X4=1,2X1－2X2－4X3＋6X4=－1的通解 用克拉默法则解下列方程组 x1-2x2+3x3-4x4=4 x2-x3+x4=-3 x1+3x2+2x4=1 -7x2+3x3+x4=3x1-2x2+3x3-4x4=4x2-x3+x4=-3 x1+3x2+2x4=1 -7x2+3x3+x4=3 (2x4-5x2-4x+1)-(3x3-5x2-3x) X2+X+1=0 X4+2X3+4X2+3X+2=? 已知x2-3x+1=0,求x4-6x3+4x2+15x+2 x4+2x3+x2+1+2(x+x2)因式分解 用矩阵法姐方程组：2x1-3x2 +x 3-x4 =3 3x 1+x2 +x3 +x 4=0 4x1 -x2 -x 3-x4 =7 -2x 1-x3 +x3 +x4 =-5 线性代数!解非其次线性方程组；【2x1+x2-x3+x4=1；4x1+2x2-2x3+x4=2；2x1+x-x3-x4=1】. x5-x4+x3-x2+x-1因式分解 X5-X4+X3+X2+X+1因式分解 1+x+x2+x3+x4=0,那1+x+x2+x3+x4+……+x2004=?注意:2 3 4 2004都表示 方 . 用初等行变换来解下列线性方程组（1）2x1-x2+3x3=3 3x1+x2-5x3=0 4x1-x2+x3=3 x1+3x2-13x3=-6(2) x1-2x2+x3+x4=1 x1-2x2+x3-x4=-1 x1-2x2+x3-5x4=5(3) x1-x2+x3-x4=1 x1-x2-x3+x4=0 x1-x2-2x3+2x4=-1/2 x1-x2+x3=1x2-x3+x4=21若x1,x2,x3,x4,x5满足方程组 x3-x4+x5=3x4-x5+x1=4x5-x1+x2=5求x2 x3 x4的值2已知 x1+x4+x6+x7=39 x2+x4+x5+x7=49 x3+x5+x6+x7=41 x4+x7=13 x5+x7=14 x6+x7=9 x1+x2+x3+x4+x5+x6+x7=9求x7的值若x1,x2,x3,x4,x5满足方程组 x1-x 1x2÷1＋2x3÷1＋3x4÷1＋4x5÷1＋5x6÷1等于? 1x2+2x3+3x4+4x5+.+15x16 1x1!+2x2!+3x3!+4x4!.nxn! 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+6x4=-1,x1-2x2-4x3+x4=-1