a2 + (2a - 6)2 = 680
a2 + 4a2 -- 24a + 36 = 680
5a2 - 24a - 644 = 0
5a2 - 70a + 46a - 644 = 0
5a(a - 14) + 46(a - 14) = 0
(5a + 46)(a - 14) = 0
5a + 46 = 0
5a = -46
a = -46/5 ------> not positive or an integer
a - 14 = 0
a = 14
2(14) - 6 = 22
14 and 22