规定一种新运算△,如:3△2=3x2-2x2=2,2△1=2x1-1x2=0,4△3=4x3-3x2=6;试计算(5△4

求线性方程组 x2-x3-x4=0 x1+x2-x3+3x4=1 x1-x2+x3+5x4=-1 x1+2x2-2x3+ 用列主元Gauss消元法解线性方程组{-x2-x3+x4=0,x1-x2+x3-3x4=1,2x1-2x2-4x3+6x 解线性方程组 求齐次线性方程组X1+X2+X3+X4=0,2X1+3X2+4X3+5X4=0,4X1+5X2+6X3+7 写出下面线性规划的对偶规划min Z=3X1+2X2+X3; X1+X2+X3≤6；X1-X3≥4；X2-X3≥3；X1 求齐次线性方程组x1+2x2+x3+x4+x5=1 2x1+4x2+3x3+x4+x5=2 -x1-2x2+x3+3x4 求一道数学题,矩阵这块的 用消元法解线性方程组 2X1-X2+3X3=3 3X1+X2-5X3=0 4X1-X2+X3= 线性方程组求解 2x1-x2+3x3=3 3x1+x2-5x3=0 4x1-x2+x3=3 x1+3x2-13x3=-6 规定△为一种新运算,A△B=3A-2B,如4△2=3x4-2x2,1/2△1/3=3x1/2-2x1/3.现已知x△(4 x1,x2,x3,是x^3+px+2=0的三个根,计算行列式 :|x1 x2 x3| |x2 x3 x1| |x3 x1 奇次线性方程组x1-2x2+3x3-4x4=0 x2-x3+x4=0 x1+3x2-kx4=0 -7x2+kx3+x4= 用消元法解线性方程X1+2X2+3X3=4 3X1+5X2+7X3=9 2X1+3X2+4X3=5 设齐次线性方程组:x1+x2+x3+x4=0,x2-x3+2x4=0,2x1+3x2+(a+2)x3+4x4=0,3x1