Suku ke 31 suatu barisan aritmatika : 8,3,-2,-7...adalah

dik : a = 8 , b = 3-8 = -5
dit : U31
jawab:
Un = a + (n-1) b
U31 = 8 + (31-1) (-5)
U31 = 8 + (30)(-5)
U31 = 8 + (-150)
U31 = 8-150 = -142

MAPEL : MATEMATIKA

KELAS : IX

BAB : BARISAN & DERET
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Nilai a = 8

Nilai b = 3 - 8 = -5

Ditanya :
↪Suku ke 31

Jawaban :

U31 = a + (n-1)b

U31 = 8 + (31-1)(-5)

U31 = 8 + (30)(-5)

U31 = 8 - 150

U31 = -142 ✔