(2X2)/1X3+(4X4)/(3X5)+(6X6)/(5X7)+...+(20X20)/(19X21)==?

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/29 17:16:54
(2X2)/1X3+(4X4)/(3X5)+(6X6)/(5X7)+...+(20X20)/(19X21)==?

(2X2)/1X3+(4X4)/(3X5)+(6X6)/(5X7)+...+(20X20)/(19X21)==?
(2X2)/1X3+(4X4)/(3X5)+(6X6)/(5X7)+...+(20X20)/(19X21)==?

(2X2)/1X3+(4X4)/(3X5)+(6X6)/(5X7)+...+(20X20)/(19X21)==?
原式=4/3+16/15+36/35+...+400/399
=1/3+1/15+1/35+...+1/399+10
=1/3+【(1/3-1/5)+(1/5-1/7)+(1/7-1/9)+...+(1/19-1/21)】÷2+10
=1/3+(1/3-1/5+1/5-1/7+1/7-1/9+...+1/19-1/21)÷2+10
=1/3+(1/3-1/21)÷2+10
=220/21

1x2+2x3+3x4+4x5+.+15x16 x1-x2+x3=1 x2-x3+x4=2 x3-x4+x5=3 x4-x5+x1=4 x5-x1+x2=5 求x1,x2,x3,x4,x5 求非齐次线性方程组的通解x1+3x2+5x3-4x4=1x1+3x2+2x3-2x4+x5=-1x1-2x2+x3-x4-x5=3x1+2x2+x3-x4-x5=3 若x1,x2,x3,x4,x5满足方程组:x1-x2+x3=1 x2-x3+x4=2 x3-x4+x5=3 x4-x5+x1=4 x5-x1+x2=5 求x2,x3,x4的少打了个字,是求x2,x3,x4的值 解一道方程组x1+x2+x3=5,x2+x3+x4=1,x3+x4+x5=-5,x4+x5+x1=-3,x5+x1+x2=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 求非其次线性方程组 {x1+2x2+x3+x4+x5=1x1+2x2+x3+x4+x5=12x1+4x2+3x3+x4+x5=2-x1-2x2+x3+3x4-x5=5 2x3+4x4-2x5=6 的一般解 解方程组:x1+x2+x3+x4+x5=7 3x1+2x2+x3+x4-3x5=-2 x2+2x3+2x4+6x5=23 5x1+4x2-3x3+3x4-x5=10 求线性方程组的全部解,并用对应导出组的基础解系表示X1+3X2+5X3-4X4=1 X1+3X2+2X3-2X4+X5=-1 X1-2X2+X3-X4-X5=3 X1-4X2+X3+X4-X5=3 X1+2X2+X3-X4+X5=-1 简算:1/1x2+1/2x3+1/3x4+1/4x5 1/1x2 + 1/2x3 + 1/3x4 + 1/4x5 已知数据x1,x2,x3,x4,x5的平均数是20,那么另一组数据x1,x2+1,x3+2,X4+3,X5+4的平均数 求下列非齐次线性方程组的通解(1){x1+x2+x3+x4+x5=2;x1+2x2-4x5=-2;x1+2x3+2x4+6x5=6;4x1+5x2+3x3+3x4-x5=4}(2){x1-x2+5x3-x4=1;x1+x2-2x3+3x4=1;2x1+3x3+2x4=2;2x1+4x2-11x3+10x4=2}(3){x1+x2+x3+x4+x5=1;3x1+2x2+x3+x4-3x5=0 求解线性方程组 x1-2x2+3x3-x4-x5=2 x1+x2-x3+x4-2x5=1 2x1-求解线性方程组x1-2x2+3x3-x4-x5=2x1+x2-x3+x4-2x5=12x1-x2+x3-2x5=22x1+2x2-5x3+2x4-x5=5 简算.1/1X2+1/2X3+1/3X4+1/4X5+.+1/199X200, 1x2/1+2x3/1+3x4/1+4x5/1+…+39x40/1 求1/(1x2)+1/(2x3)+1/(3x4)+1/(4x5)+.+1/(2005x2006) 1/1x2+1/2x3+1/3x4+1/4x5.1/9x10简算 1/1x2+1/2x3+1/3x4+1/4x5+.1/49x50