selesaikan persamaan 3^x . 81^y = 27 dan 2^x . 8^y= 1/16

Materi Eksponen [tex] 3^x \times 81^y = 27 \\ 3^x \times 3^{4y} = 3^4 \\ 3^{x+4y} = 3^4 \\ x + 4y = 4 (...1) [/tex]
Selanjutnya, [tex] 2^x \times 8^y = \frac{1}{16} \\ 2^x \times 2^{3y} = 2^{-4} \\ 2^{x+3y} = 2^{-4} \\ x+3y = -4 (...2) [/tex] Eliminasi x,
x + 4y = 4
x + 3y = -4
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y = 8, sehingga
x = 4 - 4y = 4 - 4(8) = -28.
Penyelesaiannya adalah x = -28 dan y = 8