Răspuns:
Explicație pas cu pas:
1
3000 m........................2100femei
100%..............................x=2100×100/3000=70%
2
(2x+1)/3x=5/6 6(2x+1)=15x 12x+6=15x 3x=6
x=2
3
(5x+4y)/5x=13/5 5(5x+4y)=65x 25x+20y=65x
20y=40x y=2x ⇒ x/y=1/2
