kerjakanlah nilai mutlak dibwah ini |2x| + |x+4| = 20 mohon dibantu yah..

|2x| + |x + 4| = 20
2x + x + 4 = 20
3x + 4 = 20
3x = 20 - 4
3x = 16
x = 16/3
2x + x + 4 = -20
3x + 4 = -20
3x = -20 - 4
3x = -24
x = -8
HP = {-8, 16/3}

|2x| =
1) 2x jika x ≥ 0
2) -2x jika x < 0

|x + 4| =
1) x + 4 jika x ≥ -4
2) -x - 4 jika x < -4

|2x| + |x + 4| = 20

1) jika x < -4
-2x + (-x - 4) = 20
-3x = 24
x = -8 (memenuhi karena x < -4)

2) -4 ≤ x < 0
-2x + (x + 4) = 20
-x = 16
x = -16 (tdk memenuhi karena -4 ≤ x < 0)

3) x ≥ 0
2x + (x + 4) = 20
3x = 16
x = 16/3 (memenuhi karena x ≥ 0)

Jadi HP = {-8, 16/3}