How do I go about showing this:

Let $\displaystyle W= Span$ $\displaystyle \left\{ v_1, ....., v_p \right\} $. Show that if $\displaystyle x $ is orthogonal to each $\displaystyle v_j $, for $\displaystyle 1 \leq j \leq p $, then $\displaystyle x $ is orthogonal to every vector in $\displaystyle W $.