2*(x/2-100)=2x-400

x-2x+3x-4x+5x.+99x-100x=25求解 2x+3x+4x+5x+x+6x+7x=100 400=x^2+(x+x)^2 x+2x+3x+.+100x f(x)=x^2+x (x （20-2x)(20-2x)x>400 x=? 1/X(X+1)+1/(X+1)(X+2)+1/(X+2)(X+3).+1/(X+99)(X+100)= 解方程：2x+4x+6x...+100x=1-(x+3x+5x+...+99x) 1X+2X+3X…+98X+99X+100X=50500X X等于多少? 1x+2x+3x+4x+5x+6x+7x…+99x=100 100(X - 2) + 10X + 2X = 100*2X + 10X + X - 2 - 495 100×2x+10x+3x+216=100×3x+10×2x+x 设函数f(x)=(x-1)(x-2)...(x-100)(x>100),求F'(X) f(x)=x(x-1)(x-2)…(x-99)(x-100),求f'(100) 解方程:x-2x+3x-4x+...+99x-100x=25 解方程：x-2x+3x-4x+.+99x-100x=25 x-2x+3x-4x+...+99x-100x=25 x^2=x