A normal vector is the set of coefficients of x, y, and z when the equation is written in standard (or general) form.
Subtracting the left side, we have
... 2(8 -y) -z +5(x -2) = 0
... 16 -2y -z +5x -10 = 0
... 5x -2y -z +6 = 0 . . . . . general form
A normal vector is (5, -2, -1).