Answer:
2[tex]\sqrt{15}[/tex]
Step-by-step explanation:
([tex]\sqrt{80}[/tex] + [tex]\sqrt{20}[/tex]) ÷ [tex]\sqrt{3}[/tex] =
= (√4·4·5 + √4·5) ÷ [tex]\sqrt{3}[/tex]
= (4[tex]\sqrt{5}[/tex] + 2[tex]\sqrt{5}[/tex]) ÷ [tex]\sqrt{3}[/tex]
= 6[tex]\sqrt{5}[/tex] ÷ [tex]\sqrt{3}[/tex]
at this point you want to rationalize the denominator, meaning multiply the numerator and denominator by [tex]\sqrt{3}[/tex]
= (6√5·3) ÷ √3·3
= 6[tex]\sqrt{15}[/tex] ÷ 3
= 2[tex]\sqrt{15}[/tex]
