计算:21×3.14-31×3.14=_________.
-15a2+5a=________(3a-1);
因式分【解析】km+kn=_________;
3a2-6ab+a=_________(3a-6b+1);
多项式32p2q3-8pq4m的公因式是_________;
ma+mb+mc=m(________);