nilai mutlak dari (x+1)+(2x-4)=9

|x + 1| + |2x - 4| = 9

•
x + 1 + 2x - 4 = 9
3x = 9 + 3
x = 4

•
x + 1 + 2x - 4 = -9
3x = -9 + 3
x = -2

HP = {-2 , 4}