Question

Dterminati numerele naturale x si y astfel incat : x/y=2/5 si x+y=98 , x/y=3/7 si y-x=24

Answer 1

[tex]\frac{x}{y}=\frac{2}{5} \Rightarrow x=\frac{2y}{5}\\ x+y=98\\ \frac{2y}{5}+y=98 |*5\\ 2y+5y=490\\ 7y=490 \Rightarrow y=70\\ x=\frac{2*70}{5}\\ x=\frac{140}{5}=28\\ .....................................\\ \frac{x}{y}=\frac{3}{7} \Rightarrow x=\frac{3y}{7}\\ y-x=24\\ y-\frac{3y}{7}=24|*7\\ 7y-3y=168\\ 4y=168 \Rightarrow y=42\\ x=\frac{3*42}{7}\\ x=\frac{126}{7}=18[/tex]