tentukan nilai x yg memenuhi persamaan |x-1|+|x-3|=19 mohon bantuannya

*memakai 2 cara, maaf jika salah :)

| x-1 | + | x-3| = 19
x-1 + x-3 = 19
x + x - 1 - 3 = 19
2x - 4 = 19
2x = 19+4
2x = 23
x = 23/2
x = 11 1/2

| x-1 | + | x-3| = -19
x-1 + x-3 = -19
x + x - 1 - 3 = -19
2x - 4 = -19
2x = -19+4
2x = -15
x = -15/2
x = -7 1/2
x = 7 1/2