" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
Verified answer
Sn = 2n² - 6nS1 = 2(1²) – 6(1) = 2 – 6 = -4
S2 = 2(2²) – 6(2) = 8 – 12 = -4
S3 = 2(3²) – 6(3) = 18 – 18 = 0
Un = Sn – S(n-1)
U1 = S1 – S0 = -4 – 0 = -4
U2 = S2 – S1 = -4 – (-4) = 0
U3 = S3 – S2 = 0 – (-4) = 4
dst......
beda = U2 – U1 = 0 – (-4) = 4
maaf kalo salah
Matematika SMP Kelas VIII
Aritmatika
Sn = 2n² - 6n
Un = Sn - S(n - 1)
= 2n² - 6n - (2 (n - 1)² - 6 (n - 1))
= 2n² - 6n - (2 (n² - 2n + 1) - 6n + 6)
= 2n² - 6n - (2n² - 4n + 2 - 6n + 6)
= 2n² - 6n - (2n² - 10n + 8)
= 2n² - 6n - 2n² + 10n - 8
= 4n - 8
b = U2 - U1
= (4 . 2 - 8) - (4 . 1 - 8)
= 0 + 4
= 4