Jawabanmu

2014-01-31T20:19:48+07:00
Un = a + (n-1)b

U₄ + U₈ = -46
(a + 3b) + (a + 7b) = -46
2a + 10b = -46  dibagi 2  = a + 5b = -23


a+ 5b = U
₆ = -23