求1x2,2x3,3x4,4x5.99x100.前99项的倒数之和.

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 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 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 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, 若X1,X2,X3,X4,X5 满足方程组：2X1+X2+X3+X4+X5=6,①X1+2X2+X3+X4+X5=12 ②X1+X2+2X3+X4+X5=24 ③X1+X2+X3+2X4+X5=48 ④X1+X2+X3+X4+2X5=96 ⑤⑴求X1+X2+X3+X4+X5的值；⑵求3X3+2X4-X5有必要说明一下,凡是跟在X后面的数字都是小 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 1x2+2x3+3x4+4x5+.+15x16 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 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 已知X2-X-1=0求,X5-X4-3X3+3X2+X的值 x5-x4+x3-x2+x-1因式分解 X5-X4+X3+X2+X+1因式分解 求1/(1x2)+1/(2x3)+1/(3x4)+1/(4x5)+.+1/(2005x2006) 因式分解X5-X4+2X3-2X2+2X-4 因式分解：x5-3x4+2x3-x2+3x-2 因式分解：x5-2x4-3x3+x2-2x-3 求1x2,2x3,3x4,4x5.99x100.前99项的倒数之和.