Matematika tolong dijawab ya ya ya​

mylesmosciskiulv – April 07, 2023

tolong dijawab ya ya ya​ 1.
Sn = 2n^2 + 3n
S1 = a = 2(1)^2 + 3(1)
= 2 + 3 = 5

S2 = 2(2)^2 + 3(2)
= 2(4) + 6
= 8 + 6 = 14

U2 = S2 - S1
= 14 - 5
= 9

b = U2 - a
= 9 - 5
= 4

Maka, a=5 ; b=9


2.
Sn = 3n^2 - n
Dit : U25 =...?

S25 = 3(25)^2 - 25
= 1875 - 25
= 1850

S24 = 3(24)^2 - 24
= 1728 - 24
= 1704

U25 = S25 - S24
= 1850 - 1704
= 146 [answer.2.content]