Jawabanmu

2014-08-11T21:21:57+07:00
Diket = 1/a+1/b=7 dan 1/a-1/b=3

(1/a)² - (1/b)²
= (1/a + 1/b)(1/a - 1/b)
= (7)(3)
= 21
1 5 1