In order for (1,3) to be a solution of the inequalities system it must fultill all of them, for that reason we know that x=1 and y=3 and replace in both of the equations
(1,3) is not a solution to the system because it doesn´t fulfill any of the equations; it creates 2 false statements because 3 is not greater that 3, but its the same and also 3 is not less than -3 but the opposite.