Question

Ex 6 repede va rogffgggvggggggggghghhy

Answer 1

[tex]a)\ \it \dfrac{3^{-4}}{3^{-7}} = \dfrac{3^{-4}}{3^{-4}\cdot3^{-3}} = \dfrac{1}{3^{-3}} = 3^3=27 \\\;\\ \\\;\\ a') \ \dfrac{3^{-4}}{3^{-7}} =3^{-4}:3^{-7} =3^{-4-(-7)} =3^{-4+7} =3^3=27 \\\;\\ \\\;\\ a'') \ \dfrac{3^{-4}}{3^{-7}} =\dfrac{\dfrac{1}{3^4}}{\dfrac{1}{3^7}} = \dfrac{1}{3^4} :\dfrac{1}{3^7}= = \dfrac{1}{3^4} \cdot\dfrac{3^7}{1}= = \dfrac{3^7}{3^4}= 3^7:3^4 =3^3=27[/tex]

$\it b)\ 5^{-11}\cdot5^9=5^{-11+9} =5^{-2} =\dfrac{1}{5^2}=\dfrac{1}{25}$