Question

$\sqrt{5} (4\sqrt{2} +3\sqrt{5} )-2(2\sqrt{10} +3)$

Answer 1

$\sqrt{5} (4 \sqrt{2} + 3 \sqrt{5} ) - 2(2 \sqrt{10} +3 ) \\ = 4 \sqrt{10} + 3 \sqrt{25} - 4 \sqrt{10} - 6 \\ = 3 \sqrt{25} - 6 = 3 \times 5 - 6 = 15 - 6 = 9$