(-1,-1,3) x (-1,0,2)
\\\begin{pmatrix} -1&-1&3 \\ \end{pmatrix} &\times \begin{pmatrix} -1& \\ 0&\\ 2& \end{pmatrix} \\\\ =(-1*-1)+(-1*0)+(3*2))\\=1+0+6\\=7
Melody has given the dot product - a scalar - of these two vectors...
However....if the cross-product was wanted, we have
(-1,-1,3) x (-1,0,2) = (u1, u2, u3) x (v1, v2, v3) = (s1, s2, s3)
s1 = [-1*2] - [3*0] = -2 - 0 = -2
s2 = [3*-1] - [-1*2] = -3 - (-2) = -3 + 2 = -1
s3 = [-1*0] - [-1* -1 ] = 0 - 1 = -1
The cross-product produces a vector in three-space that is perpendicular to the given vectors, namely..... (-2, -1, -1)