nilai x yang memenuhi pertidaksamman|2x+1|<= 5

2x + 1 < = 5
2x < = 5 - 1
2x < = 4
2x : 2 < = 4 : 2
x < = 2

(2x + 1)² = 5²
4x² + 4x + 1 = 25
4x² + 4x - 24 = 0
(4x² - 8x) + (12x - 24) = 0
4x(x - 2) + 12(x - 2)
(4x + 12)(x - 2) = 0
4x + 12 = 0          x - 2 = 0
4x = -12                   x = 2
  x = -3

-3≤ x ≤ 2