The set $B=\lbrace x^{2}-3, \ 3x-6+2x^{2}, \ 9x-10+4x^{2} \rbrace$ is a basis for $P_2$. Find the coordinates of $p(x)=7-6x-3x^{2}$ relative to this basis:

$[p(x)]_B=$ $\left[\Rule{0pt}{3.6em}{0pt}\right.$$\left]\Rule{0pt}{3.6em}{0pt}\right.$