暖意序言 2 2025-01-10 21:17 a+b=98①,a²+b²=82²②,①²-②得,2ab=98²-82²③,③÷4得½ab=¼(98+82)×(98-82)=¼×180×16=720,都不用打草稿……
暖意序言
a+b=98①,a²+b²=82²②,①²-②得,2ab=98²-82²③,③÷4得½ab=¼(98+82)×(98-82)=¼×180×16=720,都不用打草稿……
吴侯
720