Diketahui barisan geometri, suku ke 5 = 162 dan suku ke 2 = -6. Rasio barisan tersebut adalah....
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![\bold{\underline{Solution:}}\\\\rumus\ umum:\\\boxed{U_{n}=a.r^{n-1}}\\\\sehingga\ untuk\ suku\ ke\ 5:\\U_{5}=a.r^{4}=162..............(1)\\\\untuk\ suku\ ke\ 2:\\U_{2}=a.r=-6.............(2)\\\\sehingga\ subtitusi\ persamaan:\\a.r^{4}=162\\a.r.r^{3}=162\\(-6).r^{3}=162\\r^{3}= \frac{162}{-6}\\r^{3}=-27\\r= \sqrt[3]{-27}\\r=-3](https://tex.z-dn.net/?f=%5Cbold%7B%5Cunderline%7BSolution%3A%7D%7D%5C%5C%5C%5Crumus%5C+umum%3A%5C%5C%5Cboxed%7BU_%7Bn%7D%3Da.r%5E%7Bn-1%7D%7D%5C%5C%5C%5Csehingga%5C+untuk%5C+suku%5C+ke%5C+5%3A%5C%5CU_%7B5%7D%3Da.r%5E%7B4%7D%3D162..............%281%29%5C%5C%5C%5Cuntuk%5C+suku%5C+ke%5C+2%3A%5C%5CU_%7B2%7D%3Da.r%3D-6.............%282%29%5C%5C%5C%5Csehingga%5C+subtitusi%5C+persamaan%3A%5C%5Ca.r%5E%7B4%7D%3D162%5C%5Ca.r.r%5E%7B3%7D%3D162%5C%5C%28-6%29.r%5E%7B3%7D%3D162%5C%5Cr%5E%7B3%7D%3D+%5Cfrac%7B162%7D%7B-6%7D%5C%5Cr%5E%7B3%7D%3D-27%5C%5Cr%3D+%5Csqrt%5B3%5D%7B-27%7D%5C%5Cr%3D-3 "\bold{\underline{Solution:}}\\\\rumus\ umum:\\\boxed{U_{n}=a.r^{n-1}}\\\\sehingga\ untuk\ suku\ ke\ 5:\\U_{5}=a.r^{4}=162..............(1)\\\\untuk\ suku\ ke\ 2:\\U_{2}=a.r=-6.............(2)\\\\sehingga\ subtitusi\ persamaan:\\a.r^{4}=162\\a.r.r^{3}=162\\(-6).r^{3}=162\\r^{3}= \frac{162}{-6}\\r^{3}=-27\\r= \sqrt[3]{-27}\\r=-3")
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