Doua numere naturale....

Explicație pas cu pas:
a/2=b/5=k
a=2k
b=5k
a+b=84
2k+5k=84
7k=84
k=12
a=2k=12•2=24
b=5k=5•12=60
x/100•b=a
x/100•60=24
×/5•3=24
×/5=8
×=40
a/2=b/5=k
a=2k
b=5k
a+b=84
2k+5k=84
7k=84
k=12
a=24
b=60
x/100 · b=a
x=24·100/60
x=40‰
Succes!