Aduh,, tolong ding

Barisan aritmatika U2=5 dan u5 = 14 tentukan :

a.beda barisan
B.suku pertama
C.u8
D.s10

• U2 = 5
• U5 = 14

beda barisan
= 14 – 5 / U5 – U2
= 9 / 3
= 3

suku pertama
a + 4b = 14
a + 4 (3) = 14
a + 12 = 14
a = 2

U8 = a + 7b
U8 = 2 + 7 (3)
U8 = 2 + 21
U8 = 23

Sn = n/2 (2a + (n – 1) b
S10 = 10/2 (2.2 + (10 – 1) 3
S10 = 5 (4 + 9(3)
S10 = 5 (4 + 27)
S10 = 5 (31)
S10 = 155

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Kelas : 9

Mapel : Matematika

Bab : Barisan dan Deret Bilangan

Kode : 9.2.6

Kata Kunci : Barisan aritmatika, beda, suku pertama, brainly

u2= 5

u5= 14

a)beda

=14-5 / 5-2

=9/3

= 3

b)suku pertama

a +b = 5

a+ 3 = 5

a= 5-3

a= 2

c)u8

Un = a +(n-1) b

U8= 2 +(8-1) 3

= 2 +21

=23

d) S10

Sn = n/2 {2a +(n-1) b }

S10= 10/2 {2 . 2 +(10-1) 3

= 5 (4 +27)

= 5 (31)

=155