Am nevoie rapid de rezolvare, va roog la 2 și 3

[tex] \frac{x}{2} = \frac{y}{3} = \frac{z}{4} = k[/tex]
=>2k+3k+4k=45
K=45:9=>k=5=>
X=2k=10
Y=3k=15
Z=4k=20
A/5=b/6=c/7=k
=>a=5k
b=6k
c=7k
=>k=7k+6k+5k=360
=>k=360:18=20
B=6*20=120
C=7*20=140
A=5*20=100