=√ 15-√ 1/5-√45

=√ 15- 1/5√5-3√5

=√ 15- 16/5√5

2. Root number 8 Root number 24* Root number 3

=(√24*√3)/√8

=(√8*√3*√3)/√8

=3

3. (Cubic radical number 15- radical number 12)/ Quadratic radical number 3

=(3/4√ 15-√ 12)/√3÷2

=2(3/4√ 15-√ 12)/√3

=(3/2√ 15-2√ 12)/√3

=3/2√5-2*2

=3/2√5-4