cách làm : (x - 15) + |x + 5| = x - 2

(x - 15) + |x + 5| = x - 2 x-15+|x + 5| = x - 2 |x + 5| = x - 2 - x + 15 |x + 5| = x - x - 2 + 15 |x + 5| = 0 -2 +15 |x + 5| = 13 x + 5 = 13 hay x + 5 = -13 x = 13 - 5 hay x = -13 - 5 x = 8 hay x = -18