5) | x-1| = 2x+3
Th1: x-1 = 2x +3
x -2x = 3 +1
-x = 4
x=-4
Th2: x-1 = -(2x +3)
x-1 = -2x -3
x+2x = -3 +1
3x = -2
x= -2/3
Vậy x= -4 và x=-2/3
6) | 1/3x - 4/3| = 1-4/3x
Th1: 1/3x - 4/3 = 1- 4/3x
1/3x + 4/3x = 1 +4/3
5/3x = 7/3
x= 7/3 : 5/3
x= 7/5
Th2: 1/3x - 4/3 = -(1 - 4/3x)
1/3x - 4/3 = -1 + 4/3x
1/3x - 4/3x = -1 +4/3
-x = 1/3
x=1/3
Vậy x= 7/5 và x=1/3