解答下列各题:(1)计算:①2x3-2xy+2(x3+xy-6).②(?6)2×|79?1112|?(?3)(2)化简:4x2y-[3x2y-(-5xyz)]+|-8xyz|-7x2y(3)求解10(a-b2)+2(a-b2)-9(a-b2)的值,其中a=1,b=2.