计算: (1)-3-5+12; (2)(-81)÷×÷(-16); (3)-32-25×(-)2; (4)-24×(-+-); (5)-14-(1+0.5)×÷4; (6)-22×-(-1)2÷(-)-(-1)5.
计算:.
已知:如图,在等边三角形ABC的AC边上取中点D,BC的延长线上取一点E,使CE=CD.求证:BD=DE.
如图,在△ABC中,AB=AC,点D、E在BC上,且BD=CE. 求证:△ABE≌△ACD.
计算: (1)3(3x﹣4); (2)(10﹣15)÷5x.
计算: