n=16
sqrt(20)+sqrt(500)+sqrt(80)=nsqrt(5)
Switch around terms
n*sqrt{5}=sqrt{20}+sqrt{500}+sqrt{80}
Find radicals of sqrt{20}, sqrt{500} and sqrt{80}
sqrt{20}= 2 sqrt{5}
sqrt{500} = 10 sqrt{5}
sqrt{80} = 4 sqrt{5}
Then add radicals together
n*sqrt{5}=16sqrt{5}
Divide by sqrt{5}
n=16