Question

Determinati nr natural n stiind ca urmatoarele propozitii sunt adevarate:a)60 supra 40=9supra n. b)2n+1supra 7=15supra 21..

Answer 1

Răspuns

$\frac{60}{40} =\frac{9}{n} =>60n=9*40=>n=360:60=>n=6\\ \\ \frac{2n+1}{7} =\frac{15}{21} =>21(2n+1)=15*7=>42n+21=105=>42n=105-21=>\\ n=84:42=>n=2$