Pertanyaan
suku ke-9 dan suku-13 barisan aritmetika berturut- turut 18 dan 34. nilai suku ke-18 barisan tersebut adalah ?
Ditanyakan oleh: USER7387
116 Dilihat
116 Jawaban
Jawaban (116)
Un = bn + a - b
U9 = 9b + a - b
18 = 8b + a
Un = bn + a - b
U13 = 13b + a - b
34 = 12b + a
18 = 8b + a
34 = 12b + a
------------------ -
-16 = -4b
b = -16/-4
b = 4
18 = 8b + a
18 = 8.4 + a
18 = 32 + a
a = 18 - 32
a = -14
Un = bn + a - b
U18 = 4.18 + (-14) - 4
= 72 - 18
= 54
U9 = 9b + a - b
18 = 8b + a
Un = bn + a - b
U13 = 13b + a - b
34 = 12b + a
18 = 8b + a
34 = 12b + a
------------------ -
-16 = -4b
b = -16/-4
b = 4
18 = 8b + a
18 = 8.4 + a
18 = 32 + a
a = 18 - 32
a = -14
Un = bn + a - b
U18 = 4.18 + (-14) - 4
= 72 - 18
= 54
U9 = a + 8b = 18
U13= a + 12b = 34 -
------------------------ dieliminasi
4b = 16
b = 4
a+8(4)=18
a+ 32= 18
a= -14
U18 = a+17b
= -14 + 17(4)
= -14 + 68
= 54
U13= a + 12b = 34 -
------------------------ dieliminasi
4b = 16
b = 4
a+8(4)=18
a+ 32= 18
a= -14
U18 = a+17b
= -14 + 17(4)
= -14 + 68
= 54