Question

-8,-2,4,10 suku ke20

Answer 1

Diketahui :
a = -8
U2 = -2
U3 = 4

Ditanya :
U20?

Jawab :
b = U3 - U2 = U2 - a
b = 4 - (-2) = -2 - (-8)
b = 6

Un = a + (n - 1)b
U20 = -8 + (20 - 1)6
U20 = -8 + (19)6
U20 = -8 + 114
U20 = 106