Jawabanmu

2014-04-15T14:10:03+07:00
A = 3
b = 7-3 = 4

Un = a+(n-1)b
U45 = 3+(45-1)4
U45 = 3+176
U45 = 179
2014-04-15T14:11:35+07:00
Un = a + (n-1) x b
45 = 3 + 45-1 x 4
     = 3 + 44 x 4
     = 3 +176
= 179