Let $\vec { v } _ { 1 } = 2 \vec { i } - 4 \vec { j } + \vec { k }$

Let $\vec { v } _ { 1 } = 2 \vec { i } - 4 \vec { j } + \vec { k }$ and $\vec { v } _ { 2 } = 4 \vec { i } + \vec { j } + \vec { k }$ Find a vector which is perpendicular to $\vec { v } _ { 1 }$ and $\vec { v } _ { 2 }$ to find an equation of the plane through the point (1, 2, -1)and with normal vector perpendicular to both $\vec { v } _ { 1 }$ and $\vec { v } _ { 2 }$ .Express your answer in the form $A x + B y + C z = D$