3x+3.6=7.89 2x-2.8×2=10.4 怎样验算

小学六年级下册数学解方程.. 要详细的.. 还要过程 都写下来...2x+3x=60 3.6x-2.8x=12 100x-x=198 18x+2x+60 5x+6x=12.1 6.6x-5x=8 4x-x=24 1.5x-x=1 1.9x+0.4x=9.2 (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 x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x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 || x-o.8x=6 12x-8x=4.8 3x-8=16 7.5x-2x x-0.7x=3.6 求答案 (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(x-2)-2x(x+1)-3x(x-5) 其中x=负½ 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+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 x(x*x-6x-9)-x(x*x-8x-15)+2x(3-x) X+X+X+(X-1)+(X-2)+(X-3)+(X-4)=10(X-3)+(X-4) x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? x^4+x^3+x^2+x+1=0,x^2006+x^2005+x^2004+x^2003+x^2002