13,17,21,25 suku ke - 45

Kelas 8 Matematika
Bab Barisan dan Deret Bilangan

b = U2 - U1
b = 17 - 13
b = 4

U45 = a + 44 . b
U45 = 13 + 44 . 4
U45 = 13 + 176
U45 = 189

≡ penyelesaian :

⇔U₁ = a = 13

⇔b = U₂ - U₁
⇔b = 17 - 13
⇔b = 4

Un = a + ( n - 1 ) b
U₄₅ = 13 + ( 45 - 1 ) 4
U₄₅ = 13 + 44( 4 )
U₄₅ = 13 + 176
U₄₅ = 189

[tex]~[/tex]