Simplify:
Radical 27 + radical 81

Step-by-step explanation:
Given:
[tex] \cfrac{ \sqrt{27} + \sqrt{81} }{3}[/tex]
Solution:
[tex] = \cfrac{ \sqrt{27} + \sqrt{9 {}^{2} } }{3} [/tex]
[tex] = \cfrac{3 \sqrt{3} + 9 }{3}[/tex]
[tex] = \cfrac{3 \sqrt{3} + 3 \times 3}{3}[/tex]
[tex] = \cfrac{3 (\sqrt{3} + 3)}{3}[/tex]
[tex] = \cfrac{ \cancel{3}( \sqrt{3} + 3) }{ \cancel3} [/tex]
[tex] = \sqrt{3} + 3[/tex]
[tex] \approx4.7[/tex]