ada yang bisa? tolong bantuu, aku kasih 15 poin

Un = a + (n -1)b.
U5 = a + 4b = 14
U8 = a + 7b = 29
----------------------- -
-3b = -15
b = -15/-3
b = 5
a + 4b = 14
a + 4.5 = 14
a + 20 = 14
a = 14 -20
a = -6
b) U12 = a + 11b.
= -6 + 11.5
= -6 + 55
= 49
c) Un = a + (n -1)b
Un = -6 + (n -1).5
Un = -6 + 5n -5
Un = 5n -11
U1 = 5.1 -11 = -6
U2 = 5.2 -11 = -1
U3 = 5.3 -11 = 4
=> -6, -1, 4, 9, 14, 19, 24, 29, 34, 39