Question

Помогите решить 5 номеер

Answer 1

$sqrt{(6-2 sqrt{5} )(6+2 sqrt{5} )} = sqrt{36-20} = sqrt{16} =4$
$sqrt{(19-6 sqrt{10} )(5+2 sqrt{10}) } = sqrt{95+38 sqrt{10}- 30 sqrt{10}+120 } =$$sqrt{8 sqrt{10}-25 }$