kak tolong jawab ya please

Bab Nilai Mutlak
Matematika SMA Kelas X

|x - 1| = | 3x |

(x - 1)² = (3x)²
(x - 1)² - (3x)² = 0
(x - 1 + 3x) (x - 1 - 3x)= 0
(4x - 1) (-2x - 1) = 0
4x - 1 = 0
4x = 1
x = 1/4

-2x - 1 = 0
-2x = 1
x = 1/-2
x = -1/2

HP = { -1/2, 1/4 }