已知0已知0已知0根据已知可得:x-1 < 0 所以,原式 = | x | - | x-1| = X +X -1 = 2X -1
已知0根据已知可得:x-1 < 0 所以,原式 = | x | - | x-1| = X +X -1 = 2X -1