Diketahui suatu barisan geometri U6= 864 dan U10 = 54 Ditanya suku yg ke 3 dari barisan trsebut

[tex]u6 = 864 \\ a {r}^{5} = 864 \\ u10 = 54 \\ a {r}^{9} = 54 \\ a {r}^{5} {r}^{4} = 54 \\ {r}^{4} = \frac{54}{864} \\ {r}^{4} = \frac{1}{16} \\ {r}^{4} = { \frac{1}{2} }^{4} \\ r = \frac{1}{2} [/tex]
[tex]a {r}^{5} = 864 \\ a { \frac{1}{2} }^{5} = 864 \\ a = 864 \times 32 \\ a = 27648[/tex]
[tex]u3 = a {r}^{2} \\ u3 = 27648 { \frac{1}{2} }^{2} \\ u3 =27648 \times \frac{1}{4} \\ u3 = 6912[/tex]