1. \(a+b+c=-3\)
2. \(a+3b+c=9\)
3. \(a+b+3c=-19\)
Subsrtacting equation number 1 from equation number 2 we get
\(b=6\)
Substracting equation number 1 from equation number 3 we get
\(c=-8\)
Then putting \(b\) and \(c\) into equation 1
we get
\(a=-1\)
so
\(abc=-1\times-8\times6=\)48