Question

27 корень[321] - 15 корень[105]

Answer 1

27 $\sqrt{321} - 15\sqrt{105} = 3 (9\sqrt{321} -5\sqrt{105)}$

Answer 2

$27\sqrt{321}-15\sqrt{105}=27\sqrt{3*107}-15\sqrt{3*35}=27\sqrt{3}*\sqrt{107} -15\sqrt{3}*\sqrt{35} =3\sqrt{3}(9\sqrt{107}-5\sqrt{35})$