stuck, 154 bytes

Result

AC

Duration

579ms

Code [DL]

ssss["x:map(int,x.split())"mT"x:[x[3]-e for e in x]"mT]yu]u]u][["x:(x[1]*(x[5]*x[6]-x[3]*x[8])+x[2]*(x[3]*x[7]-x[4]*x[6])+x[0]*(x[4]*x[8]-x[5]*x[7]))/6"m]

stdin

10 02 50
85 54 04
45 26 78
26 05 31

stdout

5035

stderr

strace