Aflati numerele x,y,z stiind ca x reprezinta 25% din y si 20% sin z ,iar x+y+z=30
Ajutor!!


Răspuns :

x = 25 % y

y = 100x / 25 = 4x

x = 20 % z

z = 100x / 20 = 5x

x + y + z = 30

x + 4x + 5x = 30

10x = 30

x = 3

y = 4 × 3 = 12

z = 5 × 3 = 15
[tex]x+y+z=30 \\ \\ x=\frac{25y}{100} =\ \textgreater \ x= \frac{y}{4} =\ \textgreater \ y=4x \\ \\ x= \frac{20z}{100} =\ \textgreater \ x= \frac{z}{5} =\ \textgreater \ z=5x \\ \\ x+4x+5x=30=\ \textgreater \ 10x=30=\ \textgreater \ x=30:10=\ \textgreater \ x=3 \\ \\ y=4*3=12 \\ \\ z=5*3=15[/tex]