x十40%x=21,x-15%x=51,4分之3x-2分之1x=9分之1解方程

x十40%x=21,x-15%x=51,4分之3x-2分之1x=9分之1解方程 x十40%x=21,x-15%x=51,4分之3x-2分之1x=9分之1 X.(X十1)x(X十2)x(x十3) =360 x十24十x=34 15X(x十0.6)=18 40十x=3(12十x)怎么解? 18=(?)十(?)x(?) 3十x十x=5x, (x+12)X(x十12)=xXx十360 3x十9x十X=26. x的平方十x(x十4)=30, 1/(x^2一4x十3)十1/(x^2一8x十15)十1/(x^2-12x十35)十1/(x^2一16x十63)= x十5十x十6…=1000 已知1十x十x^2 十x^3=0,求x十x^2十x^3十x^4+x^5十x^6+x^7十x^8的值 x十x十x十y十y=54?x十x十y十y=46?x,y各等于多少? 5x十2x=42 15十2x一3=48 2x十3x十17=37 6x一3x=6÷5 9x一2x=15x十2x=4215十2x一3=482x十3x十17=376x一3x=6÷59x一2x=1.4十0.077(2x一6)=15.4 3x十7x十5x一7x=17十18 x乘(x十2)=x一1乘(x除2x3十40)求x=