6.45%X+(40-X)×5.6%=2.495

6.45%X+(40-X)×5.6%=2.495 x+40=2x x=? f(x)=x^2+x (x x-40%x= x^2=x (35-X)*(40-2X)+40X+2X*(35-X)=35*40 x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, 解分式方程：1/X-2+1/X-6=1/X-7+1/X-11/X-2+1/X-6=1/X-7+1/X-11/(x-2)-1/(x-1)=1/(x-7)-1/(x-6)(x-1-x+2)/(x-2)(x-1)=(x-6-x+7)/(x-7)(x-6)1/(x-2)(x-1)=1/(x-7)(x-6)(x-2)(x-1)=(x-7)(x-6)x^2-3x+2=x^2-13x+4213x-3x=42-210x=40x=4 为什么要移向才能解 x{x+1}{x-1}}x-2}{x-3}-40 x/x平方-x+2=2x/x+1 f(x)=x|x|+2x (x (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 5x+2x+x=5.6解方程 5.6+2X=11.6-3X,求X 5.6x-x=3x(5-2)求解 20/(x-20)=(2x-40)/(x+40)