Question

Daca x+y=15 si x reprezinta 25% din y,atunci x=...
explicati-mi cum vine..

Answer 1

$x= \frac{25}{100}*y= \frac{y}{4}. \\ \\ x= \frac{y}{4} \Rightarrow y=4x. \\ \\ x+y=15 \Leftrightarrow x+4x=15 \Leftrightarrow 5x=15 \Rightarrow x=3 \Rightarrow y=4*3=12. \\ \\ Solutie:~x=3~si~y=12.$

Answer 2

25\100y+y=15 amplifici pe 15 si pe y cu 100...apooi....25y+100y=1500.....125y=1500...y=1500\125....y=12.....x=25\100*12 =3