Question

Answer 1

b, \(\left|x-4\right|=4-x\)đk x =<4 

=> x - 4 = 4 - x <=> x = 4 (tm) 

c, \(\left|x+1\right|+2\left|x+1\right|=3x\Leftrightarrow3\left|x+1\right|=3x\Leftrightarrow\left|x+1\right|=x\)

đk x >= 0

TH1 : x + 1 = -x <=> 2x = -1 <=> x = -1/2 (ktm)

TH2 : x + 1 = x <=> 0 = -1 (vô lí)

 d, \(\left|x-1\right|=3x-2\)đk x >= 2/3

TH1 : x - 1 = 3x - 2 <=> x = 1/2 (ktm) 

TH2 : x - 1 = 2 - 3x <=> 4x = 3 <=> x = 3/4 (tm)