Răspuns :
2. a/2=b/6=c/-4 notam cu K
rezulta ca a=2k
b=6k
c=-4k
a+2c=42
2k+2(-4k)=42
2k-8k=42
-6k=42
k=-7
a=2(-7)=-14
b=6(-7)=-42
c=(-4)(-7)=28
rezulta ca a=2k
b=6k
c=-4k
a+2c=42
2k+2(-4k)=42
2k-8k=42
-6k=42
k=-7
a=2(-7)=-14
b=6(-7)=-42
c=(-4)(-7)=28