Odpowiedź :
5.
[tex]a) \ 7\sqrt{5}\cdot3\sqrt{3} =7\cdot3\sqrt{5\cdot3} = 21\sqrt{15}\\\\b) \ \frac{3\sqrt{5}\cdot\sqrt{6}}{2\sqrt{2}} = \frac{3\sqrt{5\cdot6}}{2\sqrt{2}} = \frac{3}{2}\sqrt{\frac{30}{2}} = \frac{3}{2}\sqrt{15}\\\\c) \ 3\sqrt[3]{3}\cdot4\sqrt[3]{7} = 3\cdot4\sqrt[3]{3\cdot7} = 12\sqrt[3]{21}[/tex]
a)
[tex]7 \sqrt{5} \times 3 \sqrt{3} = 21 \sqrt{5 \times 3} = 21 \sqrt{15} [/tex]
b)
[tex]3 \sqrt{5} \times \frac{ \sqrt{6} }{2 \sqrt{2} } = 3 \sqrt{5} \times \frac{ \sqrt{3} }{2} = \frac{3 \sqrt{5} \times \sqrt{3} }{2} = \frac{3 \sqrt{5 \times 3} }{2} = \frac{3 \sqrt{15} }{2} [/tex]
c)
[tex]3 \sqrt[3]{3} \times 4 \sqrt[3]{7} = 12 \sqrt[3]{3 \times 7} = 12 \sqrt[3]{21} [/tex]