Ada yang bisa jawab ​

Bagian A

10, 7, 4, …

a = 10

b = 7 – 10 = -3

U15 = 10 + (15 – 1)(-3)

U15 = 10 + 14(-3)

U15 = 10 + (-42)

U15 = -32

Bagian B

6, 9, 12, …

a = 6

b = 9 – 6 = 3

U30 = 6 + (30 – 1)(3)

U30 = 6 + 29(3)

U30 = 6 + 87

U30 = 93

Bagian C

20, 17, 14, …

a = 20

b = 14 – 17 = -3

U14 = 20 + (14 – 1)(-3)

U14 = 20 + 13(-3)

U14 = 20 + (-39)

U14 = 20 – 39

U14 = -19