Answer:
21[tex]\sqrt{5}[/tex]
Step-by-step explanation:
Using the rule of radicals
[tex]\sqrt{a}[/tex] × [tex]\sqrt{b}[/tex] ⇔ [tex]\sqrt{ab}[/tex]
Simplifying [tex]\sqrt{45}[/tex]
= [tex]\sqrt{9(5)}[/tex] = [tex]\sqrt{9}[/tex] × [tex]\sqrt{5}[/tex] = 3[tex]\sqrt{5}[/tex]
Then
3[tex]\sqrt{5}[/tex] + 6[tex]\sqrt{45}[/tex]
= 3[tex]\sqrt{5}[/tex] + 6(3[tex]\sqrt{5}[/tex] )
= 3[tex]\sqrt{5}[/tex] + 18[tex]\sqrt{5}[/tex]
= 21[tex]\sqrt{5}[/tex]
