计算:53°39′24〃+26°40′38〃=__________,180°-75°54′33〃=__________,54°20′÷6=__________
计算:(a2b)2÷a4= .
计算:6x3÷(﹣2x)= .
计算:(﹣2a﹣2)3b2÷2a﹣8b﹣3= .
计算:6m2÷(﹣3m2)= .
计算:(﹣2a)2÷a= .