Question

un grup de tineri pleaca la o petrecere cu masinile.daca ar urca 4 tineri in fiecare masina,2 ar ramane pe jos.daca ar urca in fiecare masina 5 tineri,in una dintre masini ar fi numai 3 tineri.cate masini si cati tineri pleaca la petrecere?

Answer 1

$x\to nr. \ de \ masini \\\\ 4x+2 \to nr. \ de \ tineri \\ 5(x-1)+3 \to nr. \ de \ tineri \\\\ 4x+2=5(x-1)+3 \\\\ 4x+2=5x-5+3 \\\\ 4x-5x=-2-2 \\\\ -x=-4 \\\\ \boxed{x=4 \ masini} \\\\ 4*4+2= \\\\ =16+2= \\\\ = \boxed{18 \ tineri}$