Question

( √ 5 - 4) x( √ 5 + √ 2)

Answer 1

$( \sqrt{5 - 4} ) \times ( \sqrt{5} + \sqrt{2} ) = \\ \sqrt{5 - 4} \sqrt{5} + \sqrt{5 - 4} \sqrt{2} = \\ \sqrt{(5 - 4) \times 5} + \sqrt{(5 - 4) \times 2} = \\ \sqrt{1 \times 5} + \sqrt{1 \times 2} = \\ \\ = \sqrt{5} + \sqrt{2} \\ \sqrt{5} + \sqrt{2} = 3.65028$