3x+2.5(68-x)=180,3x+2（68-x）=180,2.5x+2.5（68-x）=180,这三道方程怎么解

用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+. 3x+2.5(68-x)=180,3x+2（68-x）=180,2.5x+2.5（68-x）=180,这三道方程怎么解 3x*x=1600+x*x-80x (X+1)X(X+2)X(X+3)=504 一个“整式的乘法”的问题请先阅读下列解题过程,再仿做下面的问题.已知X*X + X - 1=0,求X*X*X + 2*X*X + 3的值.解X*X*X + 2X*X +3=X*X*X +X*X -X +X*X +X +3=X{X*X +X -1} +X*X +X -1 +4=0+0+4=4+ x + X*X + X*X*X=0.+ X*X + X*X*X 3道简单的分式方程,1.3/(1-x^) = 2/(1+2x+x) - 5/1-2x+x^2.5x/(x^+x-6) + (2x-5)/(x^-x-12) = (7x-10)/(x^-6x+8)3.(x+1)/(x+2) + (x+6)/(x+7) = (x+2)/(x+3) + (x+5)/(x+6) x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 如果3x*x-x=1那么9x*x*x*x+12x*x*x-3x*x-7x+2001等于多少 *-----------------------------------------------*| 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 || 3*X*X*X+3*X*X-3x-9=0 x=? (x-3/x-2)-(x-2/x-1)=(x-5/x4) -(x-4/x-3) 解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6) x-2x+3x-4x+5x.+99x-100x=25求解 x+3x+x-2+x+x+50%x=188 求x 2x+3x+4x+5x+x+6x+7x=100 x(x-2)-2x(x+1)-3x(x-5) 其中x=负½ x(x+1)+(x+2)+(x+3)+(x+4)+(x+5) = 27求x 请问这道题咋做 ：（x）X (x+1) X (x+2) X (x+3) =360