Question

Sa se afle numerele x,y,z stiind ca sunt direct proportionale cu 2,5,7 si produsul lor este 560.Multumesc ! P.S : Doresc o rezolvare cat mai clara si un raspuns rapid !

Answer 1

x/2=y/5=z/7=k;
⇒x=2k;
⇒y=5k;
⇒z=7k;
⇒2·5·7·k³=560
⇒70·k³=560⇒k³=8=2³⇒k=2;
⇒x=4;
⇒y=10;
⇒z=14;

Answer 2

$\frac{x}{2}= \frac{y}{5}= \frac{z}{7}=K$
$\frac{x}{2}=K \\ x=2K$
$\frac{y}{5}=K \\ y=5K$
$\frac{z}{7}=K \\ z=7K$
$2K*5K*7K=560 \\ 70K^{3}=560 \\ K^{3}=8= 2^{3} \\ K=2 \\ x=2*2=\boxed{4} \\ y=5*5=\boxed{10} \\ z=7*2=\boxed{14}$
$Proba:4*10*14=560$