(3+5x1)+(3+5x2)+.+(3+5x100) 如何巧算?

1x1-2x2+3x3-4x4+5x5-6x6.-100x100+101x101 已知X1 X2为方程5X平方-3X-1=0且X1＞X2求X1-X2 max z=3*x1*x1-x1^3+5*x2*x2-x2^3; x1+2*x2=0; 刚接触lingo大家看看怎么不对 用图解法求线性规划?max z = x1+3x2 5x1+10x≤50 X1+X2≥1 X2≤4 X1,X2≥0 若x1,x2│x1-x2│x2/x1+x1/x2是方程2x²;+5x-3=0的两个根 已知x1和x1是方程2x2-2x-5=0的两个实数根,求代数式x1^3+3X1^2+0.5X1+6X2 线性方程组{2x1-x2-2x3=λx1{5x1-3x2-3x3=λx2{-x1+2x3=-λx3有非零解,则λ= 求线性方程组 x2-x3-x4=0 x1+x2-x3+3x4=1 x1-x2+x3+5x4=-1 x1+2x2-2x3+ 1X2+2X4+3X6+.50X100 用消元法解线性方程X1+2X2+3X3=4 3X1+5X2+7X3=9 2X1+3X2+4X3=5 求解线性方程组x1+x2=5,2x1+x2+x3+2x4=1 5x1+3x2+2x3+2x4=3 求非齐次线性方程组的一个解x1+x2=5,2x1+x2+x3+2x4=1,5x1+3x2+2x3+2x4=3