Question

va rog ex 13dau coroana !!! se poate doar 2

Answer 1

a) 9lei/kg...........10kg
6lei/kg............xkg,
xlei/kg............. 18 kg
Prima data aflam x-ul de pe al doilea rand
$\frac{9}{6} = \frac{x}{10} = > 6x = 90 = > x = 90 \div 6 = 15kg$
Acum aflam al doilea x

$\frac{x}{6} = \frac{15}{18} = > 18x = 90 = > x = 90 \div 18 = > x = 5lei \: pe \: kg$
b) 40km/h........9h
60km/h.........x/h
xkm/h........... 12h
Primul x
$\frac{40}{60} = \frac{x}{9} = > 60x = 360 = > x = 360 \div 60 = > x = 6h$
$\frac{x}{60} = \frac{6}{12} = > 12x = 360 = > x = 30km \: pe \: ora$

c) 30saci......60kg/sac
x saci........... 45kg/sac
12 saci.........x kg/sac
$\frac{x}{30} = \frac{60}{45} = > x = 40$

$\frac{40}{12} = \frac{x}{45} = > x = 150$
d) 30..........20
x..............25
15............x
$\frac{x}{30} = \frac{20}{25} = > x = 24$
$\frac{24}{15} = \frac{x}{25} = > x = 40$
Sper ca ai înțeles cum se rezolva problemele de tipu asta