Question

porfavor me ajudem preciso disso pra amanhã !!​

Answer 1

Resposta:

Explicação passo a passo:

$a)$

$3^{9} .9^{-2} =3^{9}.(3^{2})^{-2} =3^{9}.3^{-4} =3^{(9-4)} =3^{5}$

$27^{7} .81^{-5} =(3^{3} )^{7} .(3^{4}) ^{-5} =3^{21} .3^{-20} =3^{(21-20)} =3^{1}=3$

Portanto...

$\frac{3^{5} }{3} =3^{(5-1)} =3^{4} =81$

$b)$

$(2^{-4}) ^{2}.(2^{-2}) ^{3} =2^{-8} .2^{-6} =2^{(-8-6)} =2^{-14}$

$2^{-3} .2^{-11} =2^{(-3-11)} =2^{-14}$

Portanto...

$\frac{2^{-14} }{2^{-14} } =1$