7x - |3x + 1| = x+2 (ko căn bậc ạ)

2 câu trả lời

$7x-\left|3x+1\right|=x+2$

`x<-\frac{1}{3},\ge \-\frac{1}{3}`

$⇔7x-\left|3x+1\right|-x=2$

$⇔6x-\left|3x+1\right|=2$

TH1: $6x-\left(3x+1\right)=2$

$→3x-1=2$

$→3x-1+1=2+1$

$→3x=3$

$→x=3:3$

$→x=1(tm)$

TH2: $6x-\left[-\left(3x+1\right)\right]=2$

$→6x+3x+1=2$

$→9x+1=2$

$→9x+1-1=2-1$

$→9x=1$

$→x=1:9$

$→x=\dfrac{1}{9}(ktm)$

$\text{Vậy x = 1}$

 

7x-|3x+1|=x+2
|3x+1|=7x-x+2

|3x+1|=6x+2
3𝑥+1−1=6𝑥+2−1

3𝑥=6𝑥+1

3𝑥−6𝑥=6𝑥+1−6𝑥

−3𝑥=1

𝑥=−1/3
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