Determine the solution to the system of inequalities. y greater than x minus 5 x plus y less than 4

For this case we have the following system of inequations:
 y> x-5
 x + y <4
 We must follow the following steps:
 1) Graph both equations
 2) Find the set of points that satisfy both equations simultaneously
 3) intersect both solutions
 
 The solution is given by the shaded region.
 see attached image.

The surface area would be 576 because you multiply all the numbers then multiply that number by 6