Kak tolong bantu yaaa. pakek cara jangan asal asalan​

Jawaban:

a = 3

U2 = 9

U3 = 18

U4 = 30

2a = 3

a = 3/2

3a + b = 6

3. 3/2 + b = 6

b = 3/2

U6 = 3/2 (6²) + 3/2 (6)

U6 = 54 + 9

U6 = 63

Maaf kalau salah