(19+18+17+16+15)-(14+13+12+11)和是多少?
问题描述:
(19+18+17+16+15)-(14+13+12+11)和是多少?
答
(19+18+17+16+15)-(14+13+12+11)
=(19-14)+(18-13)+(17-12)+(16-11)+15
=5+5+5+5+15
=20+15
=35