Jawabanmu

2014-08-27T09:24:21+07:00
(2√7)² + (2-√7)² - 4(2√7)(2-√7) = 95 - 20√7
2014-08-27T09:28:22+07:00
4.7+4-4√7+7-4(4√7-28)=15.7-4√7-16√7+112=127.7-20√7