Question

化简l3x+1l+l2x-1l

Answer 1

以3x+1=0和2x-1=0时的x值作为讨论的分界点
即以x=-1/3和x=1/2为分界点进行讨论
(1)当x>1/2时
l3x+1l+l2x-1l=3x+1+2x-1=5x
(2)当-1/3≤x≤1/2时
l3x+1l+l2x-1l=3x+1-(2x-1)=x+2
(3)当x<-1/3时
l3x+1l+l2x-1l=-(3x+1)-(2x-1)=-5x

Answer 2

当 2x-1≥0 即：x≥1/2时
l3x+1l+l2x-1l=3x+1+2x-1=5x
当3x+1≥0且2x-1＜0
即：-1/3≤x＜1/2时
l3x+1l+l2x-1l=3x+1-2x+1=x-2
当3x+1＜0，即x＜ -1/3时
l3x+1l+l2x-1l= -3x-1-2x+1= -5x

Answer 3

讨论3x+1和2x+1正负，确定x的取值范围，根据他们的正负去绝对值，化简之...

Answer 4

当3x+1>0,2x-1>0时x>1/2,原式=5x
当3x+1<0,2x-1<0时x<-1/3原式=-3x-1-2x+1=-5x
当3x+1<0,2x-1>0时x无解
当3x+1>0,2x-1<0时,-1/3<x<1/2,原式=3x+1-2x+1=x+2