Expression 3: "x" greater than or equal to 0 left brace, "y" greater than or equal to 0 , right brace left brace, 4 "x" plus "y" less than or equal to 12 , right brace left brace, 2 "x" plus 3 "y" less than or equal to 16 , right bracex≥0y≥04x+y≤122x+3y≤16