7.
a)
[tex]\sqrt{50} = \sqrt{25\cdot2} = \sqrt{25}\cdot\sqrt{2} = 5\sqrt{2}\\\\\sqrt{28} = \sqrt{4\cdot7} = \sqrt{4}\cdot\sqrt{7} = 2\sqrt{7}\\\\\sqrt{72} = \sqrt{36\cdot2} = \sqrt{36}\cdot\sqrt2= 6\sqrt{2}\\\\\sqrt{200} =\sqrt{100\cdot2} = \sqrt{100}\cdot\sqrt{2} = 10\sqrt{2}\\\\\sqrt{1800} = \sqrt{900\cdot2} = \sqrt{900}\cdot\sqrt{2} = 30\sqrt{2}[/tex]
b)
[tex]\sqrt[3]{16} = \sqrt[3]{8\cdot2} = \sqrt[3]{8}\cdot\sqrt[3]{2} = 2\sqrt[3]{2}\\\\\sqrt[3]{24} = \sqrt[3]{8\cdot3} = \sqrt[3]{8}\cdot\sqrt[3]{3} = 2\sqrt[3]{3}\\\\\sqrt[3]{-128} = -\sqrt[3]{64\cdot2} = -\sqrt[3]{64}\cdot\sqrt[3]{2} = -4\sqrt[3]{2}\\\\\sqrt[3]{3000} = \sqrt[3]{1000\cdot3} = \sqrt[3]{1000}\cdot\sqrt[3]{3} = 10\sqrt[3]{3}[/tex]
