计算1/6 x+1/12 x+1/7 x+5+1/2 x+4=x.一定要有步骤.............................................不是答案写出来就可以.

计算1/x×(x+3)+1/(x+3)×(x+6)+1/(x+6)×(x+9)+1/(x+9)×(x+12) 计算(1/x²+3x+2)+(1/x²+5x+6)+(1/x²+7x+12) 计算：（x+1)(x-2)(x-3)(x-6) 计算:[(x^2 - 4)/(x^2 - x - 6) + (x+2)/(x-3)] / (x+1)/(x-3) *-----------------------------------------------*| 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 || 填九宫格帮帮忙.x x 6 x x 7 x x 98 x x x 3 x 1 x x 9 x x 6 x 5 x 3 x x x 3 x x x x 1 8x x x 9 x 1 x x x2 1 x x x x 6 x x x 6 x 7 x 3 x x 1 x x 9 x 2 x x x 47 x x 8 x x 5 x x 计算：﹙﹣x﹚^4·x^3-x^7-2x^3·(-x)^4 计算：(2x-1)^2-2(x-2)(x+6) 计算：x(x^2+x-1)-(x^2-x+1) 计算【x-1】【x²+x+1】 计算:x/(1-x)-1/(x-3) 解方程3x=x+4,2.6x-8=2.4x,4x+12=10x+3 ,7x=12-×,2.5x=2x+4,5x+3=6x+1,详列计算, 计算:|3-x|+|x-1|(x>5) 计算1/[x(x+3)]+1/[(x+3)(x+6)]+.+1/[(x+15)(x+18)]=? (x-6)(x的平方+x+1)-x(2x+1)(3x-1)计算 计算：1/x(x+3)+1/(x+3)(x+6)+...+1/(x+2004)(x+2007) 计算：(2x+3)(3x-4)>(x+1)(x-1)+5x(x+3)+7 计算 2+x+3/x-1*x^2-2x+1/x^2+6x+9 计算x^2-5x+6/x^2-1/x^2+x/x-3