A:x ≥ 2,|x-2| + |x+5| = x-2 + x+5 = 62x = 3,x = 3/2 < 2,不符合前提,舍去B:-5 ≤ x < 2,|x-2| + |x+5| = 2 -x + x+5 = 6,7 = 6,在该前提下无解C:x < -5,|x-2| + |x+5| = 2 -x - x - 5 = 6-2x = 9,x = -9/2 > -5,...