We can use some Calculus common knowledge to show that and are a plane.

1 vector in 3 space forms a line

2 vectors in 3 space at most forms a plane and forms a line if they aren't lin. ind.

Since we are given that and v_2 are lin. ind., we know they form a plane.

Example:

Suppose is a normal vector to our plane then our equation would be:

Where is a point in the plane.

You are giving a point is the origin (0,0,0). All you need is a normal vector now.