3^x.81^y=27dan2^x.8^y=1/16

[tex] 3^{x}.81^{y}=27 [/tex]
[tex] 3^{x}.(3^{4})^{y}= 3^{3} [/tex]
[tex] 3^{x}.3^{4y}=3^{3}  [/tex]
[tex] 3^{x+4y}=3^{3} [/tex]
x + 4y = 3

[tex] 2^{x}. 8^{y}= \frac{1}{16} [/tex]
[tex] 2^{x}. (2^{3})^{y}= \frac{1}{2^{4} } [/tex]
[tex] 2^{x}. 2^{3y}=2^{-4} [/tex]
[tex] 2^{x+3y}= 2^{-4} [/tex]
x + 3y = -4

x + 4y = 3
x + 3y = -4
-------------- -
        y = 7

x + 3(7) = -4
   x + 21 = -4
           x = -25