Question

descompuneți nr 720 în nr invers proporționale cu 1_/3 1/5 1/10​

Answer 1

 

$\displaystyle\bf\\x;~y;~x~~i.p.~~\frac{1}{3};~\frac{1}{5};~\frac{1}{10}\\\\x\cdot\frac{1}{3}=y\cdot\frac{1}{5}=z\cdot\frac{1}{10}=k\\\\x=3k\\y=5k\\z=10k\\\\x+y+z=720\\\\3k+5k+10k=720\\\\18k=720\\\\k=\frac{720}{18}\\\\k=40\\\\ x=3k=3\cdot40=120\\y=5k=5\cdot40=200\\z=10k=10\cdot40=400$