计算:(1)m5÷m2×m;(2)(13a2b3)?(?15a2b2);(3)(a2bc)2÷(ab2c);(4)(2x2y+3xy2)-(6x2y-3xy2);(5)(4x+3)(2x-4);(6)(3a2b-2ab+2ab2)÷(ab);(7)(a+2b)2-4ab-2(a2-2b2);(8)(x+2)2-(x+1)(x-1).