diketahui barisan aritmatika suku ke-4 = 14 dan suku ke-8 = 26 Tentukan suku ke 30 dan jumlah 50 suku pertama tolong di jawabbb

U4 = U1 + 3b = 14
U8 = U1 + 7b = 26
----------------------------[-]
========> -4b =- 12
========> b = 3

U4 = U1 + (4-1)3
14 = U1 + 3.3
14 = U1 + 9
U1 = 14 - 9
U1 = 5

U30 = U1 + (30-1)3
U30 = 5 + 29.3
U30 = 5 + 87
U30 = 92

S50 = 50/2 ( 2.5 + (50-1)3)
S50 = 25 ( 10 + 147)
S50 = 25 ( 157 )
S50 = 3925

semoga membantu

u8-u4 = a+7b - a+3b
26-14 = 7b-3b
8 = 4b
2 = b
beda = 2

u4 = a+3b
14 = a+3x2
14 = a+6
8 = a
u1 = 8

u30 = a+29b
= 8+29x2
= 8+58
= 66

S30 = 30/2x(2x8+(30-1)2)
= 15 x (16+58)
= 15 x 74
= 1110

semoga membantu, maaf kalo ada salahnya