Why a Vector x Satisfying Ax=0 is Normal to a Plane

[apachesooner]

Homework Statement

b. Let A be a 2 by 3 matrix whose rows, v1 and v2 are nonzero, nonparallel vectors in R3. Why is any nonzero vector x that satisfies the equation Ax = 0 a normal vector for the plane spanned by the vectors v1 and v2? Explain your response.

Homework Equations

The Attempt at a Solution

I have no idea where to begin. Please help.

 

[LCKurtz]

Hint: If you call the row vectors of the matrix C and D, What does Ax = 0 tell you about the dot product of C and D with x?