Question

Aflati a si b daca a supra b este egal cu 3 supra 7 si 2a+5b=82

Answer 1

a supra b =3 pe 7 =k de unde rezulta ca a=3k si b=7k
inlocuim in relatia 2a+5b=82 rezulta ca 6k+35k=82,unde k=2
a=3k =6
b=7k=14

Answer 2

$\frac{a}{b}= \frac{3}{7}$
2a+5b=82
$\frac{a}{b}= \frac{3}{7}$⇒a=$\frac{3b}{7}$
$2* \frac{3b}{7} +5b=82$
$\frac{6b}{7}+ \frac{35b}{7}=82$
$\frac{41b}{7} =82$⇒41b=574⇒b=14
a=$\frac{3*14}{7}$⇒a=3*2⇒a=6