HELP PLS THIS IS DUE IN A FEW MINS

The sum of two numbers is 12 and their difference is 18 what are the two numbers

Which one ? is the answer and how to find this answer

Graph the system of inequalities presented here on your own paper, then use your graph to answer the following questions: y < 4x − 8 y is greater than or equal to negative 5 over 2 times x plus 5 part a: describe the graph of the system, including shading and the types of lines graphed. provide a description of the solution area. (6 points) part b: is the point (5, −8) included in the solution area for the system? justify your answer mathematically. (4 points)