7. Show that the system cos w+ sin x + tany z +1 ew + x = y + e can be solved for (x,y) as a function of (w, z) near the point (x, y, z, w) = (0,0,0,0). Furthermore, find the value of Jw of the function at (x, y, z, w) = (0,0,0,0). (10 points)