Here,
#e^ycosx=6+sin(xy)#
Diff.w.r.t. #x#,#"using "color(blue)"product and chain rule"#
#e^yd/(dx)(cosx)+cosxd/(dx)(e^y)=0+cos(xy)d/(dx)(xy)#
#e^y(-sinx)+cosx(e^y(dy)/(dx))=cos(xy)[x(dy)/(dx)+y*1]#
#-e^ysinx+e^ycosx(dy)/(dx)=xcos(xy)(dy)/(dx)+ycos(xy)#
#e^ycosx(dy)/(dx)-xcos(xy)(dy)/(dx)=e^ysinx+ycos(xy)#
#(dy)/(dx)[e^ycosx-xcos(xy)]=e^ysinx+ycos(xy)#
#(dy)/(dx)=(e^ysinx+ycos(xy))/(e^ycosx-xcos(xy)]#