penyelesaian dari [tex] |x + 7| = |2x + 1| [/tex]

Kelas 10 Matematika
Bab Nilai Mutlak

|x + 7| = |2x - 1|
(x + 7)² = (2x - 1)²
(x + 7)² - (2x - 1)² = 0
(x + 7 + 2x - 1) (x + 7 - 2x + 1) = 0
(3x + 6) (-x + 8) = 0
3x + 6 = 0
3x = -6
x = -6/3
x = -2

-x + 8 = 0
-x = -8
x = 8

-2 atau 8

|x+7| = |2x-1|
✐ x+7 = -(2x-1)
x + 7 = -2x + 1
x + 2x = 1-7
3x = -6
x = -2
✐ x+7 = 2x-1
x - 2x = -1-7
-x = -8
x = 8

HP = {-2 atau 8}
(E)