Question

Ini gimana ya caranya

Answer 1

@1

110
Σ 2k + k + 1
k = 1

k =1 → a = 4
k= 110 --> Un =331

Σ = 110/2 (a + Un) = 55(4+331) = 18.425

@2
Uk = (3k² + 4k) /x
substitusi k  = (1,2,3,4)
k =1 → 1/x(7)
k = 2 →1/x (20)
k = 3→ 1/x (39)
k = 4 → 1/x (64)

1/x (7 + 20 + 39 + 64) = 26
x = (7+20+39+64)/26
x = 5