怎样解释5x5=6x6?

怎样解释5x5=6x6? 6/17x5/13-5/17x6/13 简便计算 (2X2)/1X3+(4X4)/(3X5)+(6X6)/(5X7)+...+(20X20)/(19X21)==? 1x2+2x3+3x4+4x5+5x6+6x7+7x8+8x9= 1/1x2+2/1x3+3/1x4+4/1x5+5/1x6+6/1x7= 1.2×5分之三= 2.5x5分之3= 1.4x6分之5= 2.4x6分之5 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) 计算5x6和6x5用同一句乘法口决, 计算5x6和6x5用的是同一句乘法口决对不对 巧算：1x2+2x3+3x4+4x5+5x6+6x7...+8x9 1x2+2x3+3x4+4x5+5x6---+99x100=? 用秦九韶算法计算当X=3时多项式f(x)=7X7+6x6+5x5+4x4+3X3+2x2+X的值 1x2+2x3+3x4+4x5+5x6+6x7+7x8+8x9+9x10+10x11+ +nx(n+1)= 数学matlab写代码,1式：3*x1+3.5*x2+4*x3+4.5*x4+5*x5+5.5*x6+6*x7+6.5*x8=89x1+ x2+x3+x4+x5+x6+x7+x8=200≤x1≤43 0≤x2≤59 0≤x3≤39 0≤x4≤41 0≤x5≤27 0≤x6≤28 0≤x7≤34 0≤x8≤21Yn= （x1,x2,x3,x4,x5,x6,x7,x8）求各种满足 X+X6%+(12200-x)-(12200-x)x5%=12250 thanks 用matlab线性编程 min=8*x1+10*x2+7*x3+6*x4+11*x5+9*x612*x1+9*x2+25*x3+20*x4+17*x5+13*x6>=60;35*x1+42*x2+18*x3+31*x4+56*x5+49*x6>=150;37*x1+53*x2+28*x3+24*x4+29*x5+20*x6>=125;其中x>0,x 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 逐差法求加速度公式为什么要用a=（x6+x5+x4-x3-x2-x1）/9t平方 而不用a=x6-x1/5t平方