Question

Calcule: a) √320 + √20 - √180 =

Answer 1

$\sqrt{320} + \sqrt{20} - \sqrt{180} = \\ \\ \sqrt{2^6.5} + \sqrt{2^2.5} - \sqrt{2^2.3^2.5} = \\ \\ 2^3 \sqrt{5} +2 \sqrt{5} -2.3 \sqrt{5} = \\ \\ 8 \sqrt{5} +2 \sqrt{5} -6 \sqrt{5} = \\ \\ 10 \sqrt{5} -6 \sqrt{5} = \\ \\ 4 \sqrt{5}$