lua, 157 bytes

Result

AC

Duration

486ms

Code [DL]

X={}for i=-3,8 do X[i]=0
X[i]=io.read("*n")-X[i%3-3]end
print((X[0]*X[4]*X[8]+X[1]*X[5]*X[6]+X[2]*X[3]*X[7]-X[0]*X[5]*X[7]-X[1]*X[3]*X[8]-X[2]*X[4]*X[6])//6)

stdin

14 88 12
72 17 95
24 17 23
53 07 49

stdout

9620

stderr

strace