1/1x3+1/2x4+1/3x5+……+1/18x20=?

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 1/1x3+1/2x4+1/3x5+ 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 计算1/1x3+1/2x4+1/3x5+……+1/9x11=? 1/1X3+1/2X4+1/3X5……+1/9X11=?, 1/1x3+1/2x4+1/3x5+……+1/18x20=? 1x2/1+2x3/1+3x4/1+4x5/1+…+39x40/1 1x3＋2x4＋3x5＋…9x11 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 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 x5-x4+x3-x2+x-1因式分解 X5-X4+X3+X2+X+1因式分解 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 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 计算:1x3的1x3分之一加2x4的2x4分之一加3x5的3x5分之一……加2011x2013的2011x2013分之一加2012x2014的2012x2014分之一 求解一个方程急 X（1次方）+X2+X3=5 X2+X3+X4=1 X3+X4+X5=-5 X4+X5+X1=-3 X5+X1+X2=2 求X的值,