`\qquad 3|x+4|-|2x+1|=5` $(1)$
+) Nếu $x<-4$
`(1)<=>-3(x+4)+2x+1=5`
`<=>-3x-12+2x+1=5`
`<=>-3x+2x=5+12-1`
`<=>-x=16`
`<=>x=-16` (thỏa đk)
+) Nếu `-4\le x \le {-1}/2`
`(1)<=>3(x+4)+2x+1=5`
`<=>3x+12+2x+1=5`
`<=>3x+2x=5-12-1`
`<=>5x=-8`
`<=>x={-8}/5` (thỏa đk)
+) Nếu `x>{-1}/2`
`(1)<=>3(x+4)-(2x+1)=5`
`<=>3x+12-2x-1=5`
`<=>3x-2x=5-12+1`
`<=>x=-6` (không thỏa đk)
Vậy `x=-16;x={-8}/5`
