1/1x3+1/2x4+1/3x5+……+1/18x20=?
(2X2)/1X3+(4X4)/(3X5)+(6X6)/(5X7)+...+(20X20)/(19X21)==?
解方程组X2+X3+X4=1 X1+X2+X3=5 X3+X4+X5=-5 X4+X5+X1=-3 X5+X1+X2=2
求齐次线性方程组x1+2x2+x3+x4+x5=1 2x1+4x2+3x3+x4+x5=2 -x1-2x2+x3+3x4
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
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
1x2/1+2x3/1+3x4/1+4x5/1+…+39x40/1
1x2+2x3+3x4+4x5+……+10x11
X5-X4+X3+X2+X+1因式分解
x5-x4+x3-x2+x-1因式分解
1分解因式:2x4-x3-13x2-15=?2.分解因式:x5+x4+x3+x2+x+1=?3分解因式:x4-4x2+6
1/1x2+1/2x3+1/3x4+1/4x5+```````+1/2008x2009=?
1/1x2+1/2x3+1/3x4+1/4x5.1/2005x2006=?