200x+170(70-x)+100(40-x)+x-10=

200x+170(70-x)+100(40-x)+x-10= x-2x+3x-4x+5x.+99x-100x=25求解 2x+3x+4x+5x+x+6x+7x=100 （X+X)+(X-X)+(X*X)+(X/X)=100 x+2x-3x-4x+5x+6x-7x.-196x+197x+198x-199x-200x 等于多少 200x+170(70-x)+160(40-x)+150[30-(40-x)]解的步骤 0.6x(200-X)-4X=106.2 X=? 解方程：2x+4x+6x...+100x=1-(x+3x+5x+...+99x) 1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)(x+4)+...+1/(x+100)(x+101) 1x+2x+3x+4x+5x+6x+7x…+99x=100 (100-2x)(50-2x)=3600 5000-200x-100x+4x(2)=3600 4x(2)-300x+1400=0(100-2x)(50-2x)=36005000-200x-100x+4x^2=36004x^2-300x+1400=0为什么不是5000-3600=200x+100x+4x^2=300x+100x+4x^2-1400=0 200x(1-1/2)x(1-1/3)x(1-1/4)x...x(1-1/100)=? 计算:1/(x+3)(x+4)+1/(x+4)(x+5).1/(x+99)(x+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 计算1/x(x+2)+1/(x+2)(x+4)+…+1/(x+98)(x+100) *-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X ||