(+3又1/7)*(3又1/7-7又1/3)*7/22*21/22

问题描述:

(+3又1/7)*(3又1/7-7又1/3)*7/22*21/22

(+3又1/7)*(3又1/7-7又1/3)*7/22*21/22
=(22/7*7/22)*(3又1/7-7又1/3)*21/22
=(22/7-22/3)*21/22
=22/7*21/22-22/3*21/22
=3-7
=-4