100x( 3/1x4 + 3/4x7 +3/7x10 +.3/97x100)=?注：1x4、4x7、7x10等均为分母的大小

100x( 3/1x4 + 3/4x7 +3/7x10 +.3/97x100)=?注：1x4、4x7、7x10等均为分母的大小 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 lim[1/(1x4)+1/(4x7)+1/(7x10)+...+1/(3n-2)x(3n+1)]=_____ Min Z= X1 +X2 +X3 +X4 +X5 +X6 +X7 +X8S.T.2X1 +X2 +X3 +X4 =1002X2 +X3 + 3X5 +2X6 + X7 =100X1 + X3 + 3X4 +2X6 +3X7 +4X8 =100X1,X2,X3,X4,X5 ,X6,X7,X8 >=0经过计算的最优解是X*= (40 ,20,0,0,0 ,30 ,0 ,0)T Z* =90但该解也是最优解X*= (10 ,50,0 3/(1X4)+3/(4X7)+3/(7X10)+3/(10X13)+3/(13X16) 1x4+4x7+7x11+……+n(n+3)=?分解因式啊~~~ 巧算：1x2+2x3+3x4+4x5+5x6+6x7...+8x9 简便方法计算-14X4分之3-0.34X7分之3+4分之1X(-14)+7分之4X(-0.34) 求和:1/1x4+1/4x7+···+1/(3n-2)x(3n+1)要精准一点的,快~~~谢啦 1x4分之一加4x7分之一加到（3n-2）x（3n+1）分之一等于多少 x8+x7+x6 +x5+x4+x3+x2+x+1因式分解 x8+x7+x6+x5+x4+x3+x2+x+1因式分解 帮我用lingo或者lindo算个题呗?x1+x4+x5+x6+x7>20x1+x2+x5+x6+x7>13x1+x2+x3+x6+x7>10x1+x2+x3+x4+x7>12x1+x2+x3+x4+x5+>16x2+x3+x4+x5+x6+>18x3+x4+x5+x6+x7>20格式不对也改下哈,>在lingo中应该和>=一样吧?min=(5x1+4x2+3x3+3x4+3x5+3x6+4x7) (1-1/2x4)x(1-3/3x5)x(1-5/4x6)x(1-7/5x7)x(1-9/6x8)x(1-11/7x9)x(1-13/8x10)x(1-15/9x11) 1/1x3+1/2x4+1/3x5+1/4x6+1/5x7+1/6x8 1/1x2+2/1x3+3/1x4+4/1x5+5/1x6+6/1x7= 1/2x4+1/3x5+1/4x6+1/5x7+.1/8x10+1/9x11 1/2x4+1/3x5+1/4x6+1/5x7+...+1/97x99=?RT