1X2+2X3+3X4+、、、、、、+nX(n+1）
=(1/3)(1*2*3-0*1*2)+(1/3)(2*3*4-1*2*3)+(1/3)(3*4*5-2*3*4)+.+(1/3)[n*(n+1)(n+3)-(n-1)*n*(n+1)]
=(1/3)[n(n+1)(n+2)-0]
=n(n+1)(n+2)/3
1X2=1/3（1X2X3-0X1X2) 2X3=1/3(2X3X4-1X2X3) 发现1X2+2X3+3X4+、、、、
5个回答
相关问题
-
1x2=1|3(1x2x3-0x1x2) 2x3=1|3(2x3x4-1x2x3) 3x4=1|3(3x4x5-2x3x
-
1x2=1/3(1x2x3=0x1x2 ) 2x3=1/3(2x3x4-1x2x3) 3x4=1/3(3x4x5- 2x
-
(x1-x2+4x3-2x4=0;x1-x2-x3+2x4=0;3x1+x2+7x3-2x4=0;x1-3x2-12x3
-
X^3-3X^2+4=0x^3-3x^2+4=x^3+1-3x^2+3=(x^+1)(x^2+x+1)-3(x-1)(x
-
求方程组X1-3X2-2X3-X4=1 3X1-8X2-4X3-X4=0 -2X1+X2-4X3+2X4=1 -X1-2
-
x1+5x2+2x3-4x4=3 -3x1-2x2+3x3+4x4=-6 -x1+3x2-x3-4x4=-2 -2x1+
-
求非.X1+X2－X3+X4=1 ,X1－X2+X3－3X4＝1,X1－X2－2X3＋3X4=-1/2
-
线性方程组为：x1-x2-5x3+4x4=2 2x1-x2+3x3-x4=1 3x1-2x2-2x3+3x4=3 7x1
-
求线性方程组 x2-x3-x4=0 x1+x2-x3+3x4=1 x1-x2+x3+5x4=-1 x1+2x2-2x3+
-
X-(1/4+3)-1/3{(X-1/4X+3)}-2-1/2{X-(X-1/4X+3)-1/3(X+1/4X+3)-2