1. Obavi naznačene operacije s potencijam:
\( 1)\:\:3^{15}:3:3^{5} \)
\( 2)\:\:6^{21}:\left( 6^{12}\cdot 6^{7}\right) \)
\( 3)\:\:\left( \dfrac{2}{3}\right) ^{-6} \cdot \left[ \left( \dfrac{2}{3}\right) ^{5}:\left( \dfrac{2}{3}\right) ^{3}\right] \)
\( 4)\:\:4.3^{9}\cdot 4.3^{2} :4.3^{10} \)
\( 5)\:\: 2^{4}: \left( 2^{-4}\cdot 2^{5}\right) \)
\( 6)\:\:\left( \dfrac{7}{5}\right) ^{7}\cdot \left[ \left( \dfrac{7}{5}\right)^{5}:\left( \dfrac{7}{5}\right) ^{-3}\right]\)
\( 7)\:\:ab^{5}\cdot b^{-3}c\cdot a^{2}b^{5}c^{-2}\)
2. Odredi vrijednost izraza za date vrijednosti nepoznanica
\( a)\:\:4x^{2}+x^{3}y+5xy^{2}\:\:\:za\:\:\: x=2\:\:i\:\:y=-1 \)
\( b)\:\:3xy^{2}-\dfrac{2}{3}xy-1\:\:\:za\:\:\: x=-3;y=-\dfrac{1}{3}\)
