1/3X+20+(X-1/4(1/3X+20))=X-3/8X这道题怎么解?
问题描述：
1/3X+20+(X-1/4(1/3X+20))=X-3/8X这道题怎么解?
答
1/3X+20+(X-1/4(1/3X+20))=X-3/8X
4+4x（3x+20)-1=5/8x*4(3x+20)
8+8x（3x+20)-2=5x(3x+20)
6+24x^2+160x=15x^2+300x
9x^2-140x+6=0
x=140+√140^2-4*9*6/2*9=70+√4846/9
或x=140-√140^2-4*9*6/2*9=70-√4846/9有点看不懂，用六年级的水品我理解成分式方程了如为六年级1/3X+20+(X-1/4(1/3X+20))=X-3/8X1/3X+20+X-1/12X-5=5/8X1/3X+15+X-1/12X=5/8X8x+360+24x-2x=15x15x=-360x=-24