(-1/4-31/80)+(7/24+9/40)
问题描述:
(-1/4-31/80)+(7/24+9/40)
答
(-1/4-31/80)+(7/24+9/40)
=(-20/80)+7/24+18/80
=7/24-33/80
=70/240-99/240
=-29/240