Question

2 tentukan suku ke 17 dan barisan
a. 5, 10, 15.....
b. 4,,7 10.....
C. 2,-1,-4, -7....
d. -2, -7, -12,....​

Answer 1

a. U₁₇ = 85

b. U₁₇ = 52

c. U₁₇ = -46

d. U₁₇ = -82

Penjelasan dengan langkah-langkah :

– Barisan aritmatika

a. 5, 10, 15, …

• Suku pertama (a) = 5
• Beda (b) = 10 - 5 = 5

Uₙ = a + (n - 1)b

U₁₇ = 5 + (17 - 1)5

U₁₇ = 5 + (16)5

U₁₇ = 5 + 80

U₁₇ = 85

b. 4, 7, 10, …

• Suku pertama (a) = 4
• Beda (b) = 7 - 4 = 3

Uₙ = a + (n - 1)b

U₁₇ = 4 + (17 - 1)3

U₁₇ = 4 + (16)3

U₁₇ = 4 + 48

U₁₇ = 52

c. 2, -1, -4, -7, …

• Suku pertama (a) = 2
• Beda = -1 - 2 = -3

Uₙ = a + (n - 1)b

U₁₇ = 2 + (17 - 1)(-3)

U₁₇ = 2 + (16)(-3)

U₁₇ = 2 - 48

U₁₇ = -46

d. -2, -7, -12, …

• Suku pertama (a) = -2
• Beda = -7 + 2 = -5

Uₙ = a + (n - 1)b

U₁₇ = -2 + (17 - 1)(-5)

U₁₇ = -2 + (16)(-5)

U₁₇ = -2 - 80

U₁₇ = -82

Answer 2

Penjelasan dengan langkah-langkah:

a.

Un = a + ( n - 1 ) ( b )

U17 = 5 + ( 17 - 1 ) ( 5 )

U17 = 5 + 16 ( 5 )

U17 = 5 + ( 16 × 5 )

U17 = 5 + 80

U17 = 85

b.

Un = a + ( n - 1 ) ( b )

U17 = 4 + ( 17 - 1 ) ( 3 )

U17 = 4 + 16 ( 3 )

U17 = 4 + ( 16 × 3 )

U17 = 4 + 48

U17 = 52

c.

Un = a + ( n - 1 ) ( b )

U17 = 2 + ( 17 - 1 ) ( - 3 )

U17 = 2 + 16 ( - 3 )

U17 = 2 + ( 16 × ( - 3 ))

U17 = 2 + ( - 48 )

U17 = - 46

d.

Un = a + ( n - 1 ) ( b )

U17 = ( - 2 ) + ( 17 - 1 ) ( - 5 )

U17 = ( - 2 ) + 16 ( - 5 )

U17 = ( - 2 ) + ( 16 × ( - 5 ))

U17 = ( - 2 ) + ( - 80 )

U17 = - 82