用简便方法计算2+7+12+17+.192+197帮忙解答急用
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/28 16:28:36
![用简便方法计算2+7+12+17+.192+197帮忙解答急用](/uploads/image/z/651264-24-4.jpg?t=%E7%94%A8%E7%AE%80%E4%BE%BF%E6%96%B9%E6%B3%95%E8%AE%A1%E7%AE%972%2B7%2B12%2B17%2B.192%2B197%E5%B8%AE%E5%BF%99%E8%A7%A3%E7%AD%94%E6%80%A5%E7%94%A8)
用简便方法计算2+7+12+17+.192+197帮忙解答急用
用简便方法计算2+7+12+17+.192+197
帮忙解答急用
用简便方法计算2+7+12+17+.192+197帮忙解答急用
2+7+12+17+.192+197
=2+12+22+32+.+192+7+17+27+.+197
=(2+192)*20/2+(7+197)*20/2
=194*10+204*10
=1940+2040
=3980