the arithmetic sequence with the 3rd term is 41 and the 6th term is 65. the value of the 7th term is…
Jawaban:
U7 = 73
Penjelasan dengan langkah-langkah:
Diketahui :
U3 = 41
U6 = 65
Ditanya :
U7 = ?
Dijawab :
•mencari nilai b
U6 => a + 5b = 65
U3 => a + 2b = 41
disini kedua suku kita eliminasi sehingga menghasilkan :
3b = 24
b = 8
•mencari nilai a
U3 => a + 2b = 41
=> a + 2(8) = 41
=> a + 16 = 41
=> a = 25
•mencari suku Un
Un = a + ( n – 1 ) b
= 25 + ( n – 1 ) 8
= 8n + 17
•mencari nilai suku ketujuh (U7)
Un = 8n + 17
U7 = 8(7) + 17
U7 = 56 + 17