Question

27 корень[321] - 15 корень[105]

Answer 1

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

Answer 2

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