用简便方法计算39.98×26+19.99×74-199.9×2.6

来源:学生作业学帮网 编辑:学帮网 时间:2024/06/05 20:08:48

用简便方法计算39.98×26+19.99×74-199.9×2.6

39.98×26+19.99×74-199.9×2.6
=19.99×2×26+19.99×74-19.9.9×26
=19.99×(2×26+74-26)
=19.99×(26+74)
=19.99×100
=1999