Question

$\sqrt{90} +\sqrt{10$

$\sqrt{72} -\sqrt{8}$

Answer 1

$\sqrt{90}+\sqrt{10} = 3\sqrt{10} + \sqrt{10} = 4\sqrt{10}$

$\sqrt{x*72}-\sqrt{8} = \sqrt{x}*\sqrt{72}-\sqrt{8} = \sqrt{8}(\sqrt{x*9}-1) = \sqrt{8}(3\sqrt{x}-1)$