如图,已知在△ABC中,AB=BC=8,AC=6,AF⊥BC于点F,BE⊥AC于点E,取AB的中点D,则△DEF的周长为_________.
比较大小:______.
把下列各数填入相应的空格中: +1,-3.1, 0,,-1.314,-17,. (1)负数:_____________________; (2)正整数:___________________________; (3)整 数:______________________; (4)负分数:___________________________.
若,,且,则的值为________.
一个多项式与的和是,则这个多项式为________.
则的值是________.