12.5×64+53×3.71+47×3.71的简算?

简便运算一.1又1/4*17.6+36除4/5+2.64*12.5二.51又2/3除5/3+71又红又3/4除7/4+91又4/5除9/5三.1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110四.1995*(...