如图,正方形ABOC的边长为2,反比例函数y=过点A,则k的值是 .
计算:(x-3)(3x-4)=_________;
计算:(3a-2)(2a+5)=________;
计算:(a+2b)(a-b)=_________;
填空:x2y·()=2x3y-x2y2.
计算:3x2y(-4xy2)·(x3)2=_________.