7) \(\sqrt{5}\cdot\sqrt{45}=\sqrt{225}=15\)
8) \(\sqrt{52}\cdot\sqrt{13}=13\cdot2=26\)
9) \(-8\sqrt{6}\cdot2\sqrt{24}=-16\sqrt{144}=-16\cdot12=-192\)
10) \(9\sqrt{3}\cdot3\sqrt{27}=9\sqrt{3}\cdot9\sqrt{3}=243\)
11) \(\sqrt{2}\cdot\sqrt{162}=\sqrt{324}=18\)
12) \(3\sqrt{5}\cdot\left(-10\sqrt{3}\right)=-30\sqrt{15}\)
7) \(\sqrt{5}.\sqrt{45}=\sqrt{225}=15\)
8) \(\sqrt{52}.\sqrt{13}=\sqrt{676}=26\)
9) \(8\sqrt{6}.\left(-2\sqrt{24}\right)=2\sqrt{4}\sqrt{6}.\left(-2\sqrt{24}\right)=-2.\sqrt{24}.2.\sqrt{24}=-4.24=-96\)
10)\(9\sqrt{3.3}\sqrt{27}=\sqrt{3}\sqrt{9}\sqrt{27}=\sqrt{27}.\sqrt{27}=27\)
11)\(\sqrt{2}.\sqrt{162}=\sqrt{324}=18\)
