(1/3-5/21+3/14-2/7)/(-1/42)
问题描述:
(1/3-5/21+3/14-2/7)/(-1/42)
答
=(14/42-10/42+9/42-12/42)/(-1/42)
=(4/42-3/42)/(-1/42)
=(1/42)/(-1/42)
=-1