14. (2021秋•江岸区校级月考)试比较下列各组式子的大小:(1)x+1−x\sqrt{x+1}-\sqrt{x}x+1−x与x−x−1\sqrt{x}-\sqrt{x-1}x−x−1,其中x>1x>1x>1;(2)x3−2y3x^{3}-2y^{3}x3−2y3与xy2−2x2yxy^{2}-2x^{2}yxy2−2x2y,其中x>y>0x>y>0x>y>0.