Pada deret aritmetika diketahui U1 =5 dan U6 =55. Tentukan U16

≡ penyelesaian :

⇒b = U₆ - U₁ / ( 6 - 1 )
⇒b = 55 - 5 / 5
⇒b = 50 / 5
⇒b = 10

⇒maka, U₁₆ :

Un = a + ( n - 1 ) b
U₁₆ = 5 + ( 16 - 1 ) 10
U₁₆ = 5 + 15( 10 )
U₁₆ = 5 + 150
U₁₆ = 155

∴ Jadi, nilai U₁₆ adalah 155.

[tex]~[/tex]

Un = a + (n-1)b
U1 = a = 5
=>U6 = 5 + (6-1)b
55 = 5 + 5b
55-5 = 5b
50 = 5b
b = 50/5
b = 10
=> U16 = a + (n-1)b
U16 = 5 + (16 - 1)10
U16 = 5 + (15)10
U16 = 5 + 150
U16 = 155
=> jadi nilai U16 = 155