(1)计算:3(–π)0– + (–1)2011(2)先化简,再求值: – ,其中x = –3(3)如图,平行四边形ABCD的对角线AC、BD交于点O,E、F在AC上,G、H在BD上,且AF=CE,BH=DG,求证:AG∥HE
计算:(—5+23)—(—1)7;
计算:;
计算:.
计算:12÷(—3—+1);