(2/21+1/25)×21×25简算
问题描述：
(2/21+1/25)×21×25简算
答
原式=2/21*21*25+1/25*21*25
=2*25+21*1
=50+21
=71
答
答：
(2/21+1/25)×21×25
=21×25×(2/21)+21×25×(1/25)
=25×2+21×1
=50+21
=71