-3-[-5+(1-0.2x3/5)÷(-2)]计算

-3-[-5+(1-0.2x3/5)÷(-2)]计算 (5^4x3^3-5^3x3^2+5^2x3)÷15=? 设x=(1-√5)÷2则√(x3-1÷x3)x3就是x³ (-5)x3又3分之1+2x3又3分之1+(-6)x3又3分之1 1+2x3-4÷5= (3X3+5X2+X)/(7X3+5X-4) 计算：3^2010-5x3^2009+6x3^2008 简算3^2012-5X3^2011+6X3^2010 用初等行变换来解下列线性方程组（1）2x1-x2+3x3=3 3x1+x2-5x3=0 4x1-x2+x3=3 x1+3x2-13x3=-6(2) x1-2x2+x3+x4=1 x1-2x2+x3-x4=-1 x1-2x2+x3-5x4=5(3) x1-x2+x3-x4=1 x1-x2-x3+x4=0 x1-x2-2x3+2x4=-1/2 ｛2X1-X2+3X3=33X1+X2-5X3=04X1-X2+X3=3X1+3X2-13X3=-6{X1-2X2+3X3-4X4=4X2-X3+X4=-3X1+3X2-3X4=1-7X2+3X3+X4=-3 1、5/4x3+5/4 2、6/11x4/17+4/11x5/17 3、36x3/4-3÷4-3/4x3 4、23x(2/23+1/5)x5 解下列线性方程组 x1+2x2+3x3=1 2x1+2x2+5x3=2 3x1+5x2+x3=3 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 解方程组X1-2x2+3x3-x4=1,3x1-x2+5x3-3x4=2,2x1+x2+2x3-2x4=3 X1+X2-3X3-X4=1 3X1-X2-3X3+4X4=4 X1+5X2-9X3-8X4=0 解线性方程组 1.证明（8-7x-6x2+x3）+(x3+5x2+4x-1)-(-x2-3x+2x3-3)的值与x无关.快, 求证:无论X取何值下列（8-7X-6X2+X3)+(X3+5X2+4X-1)-(-X2-3X+2X3-3)结果不变 x1+5x2-x3-x4=-1x1-2x2+x3+3x4=33x1+8x2-x3+x4=1