Bantu Jawab Kak Yang B

Un = a+(n-1)b

U1 = 6 = a
U7 = 36 = a+6b
S10...?

a+6b=36
6+6b=36
6b = 30
b = 5

Sn = n/2 (2a+(n-1)b)
S10 = 10/2(2×6+9×5)
S10 = 5(12+45)
S10 = 5(57)
S10 = 285

jadikan yg terbaik ya kalau puas