如图,△ABC中,∠BAC=110°,E、G分别为AB、AC中点,DE⊥AB,FG⊥AC,则∠DAF=_____.
计算:(3a-2)(2a+5)=________;
计算:(a+2b)(a-b)=_________;
填空:x2y·( )=2x3y-x2y2.
计算:3x2y(-4xy2)·(x3)2=_________.
计算:x2y3·xyz=_________;