tolong bantu soal 1 dan 2

no. 1 dik = a=7 ,b=2
no.2 dik = a=86 ,b=-3

1.a=7
b=2
U8 = a +(n-1)b
= 7 +(8-1)2
= 7+(7)2
= 7+14 = 21
2.a=86
b=(-3)
U20 = a+(n-1)b
= 86 + (20-1)(-3)
= 86+(19)(-3)
= 86-57 = 29

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