Describe the image of the transformation T(vector x) = A(vector x) geometrically (line, plane inR^2 orR^3)

; means a new row

A = [2 1 3 ; 3 4 2 ; 6 5 7]. I multiplied this matrix by the [x1 ; x2; x3]. I got x1[2 ; 3 ; 6] + x2[1 ; 4 ; 5] + x3[3 ; 2 ; 7]. Where do I go from here? I'm thinking it's a plane inR^3 but I don't know for sure.

Thanks