Given $z=f(x,y),x=x(u,v),y=y(u,v),$ with $x(6,6)=5$ and

$y(6,6)=5,$ calculate $z_u(6,6)in$ terms $of$ some $of$ the values given $in$ the

table below.

$z_u(6,6)=\{\begin{array}{ccc}\text{:}[f_x(6,& 6)=r{f}_y(6,6)=p{x}_u(6,6)=-4y_u(6,& 6)=b]\\ f_x(5,& 5)=a{f}_y(5,5)=s{x}_v(6,6)=c{y}_v(6,& 6)=q\end{array}$