Steve's doctor has advised him to take protein supplements. he bought two brands, brand a and brand b. the table gives the amount of calcium, iron, and vitamins (in milligrams per spoonful) in each of the two brands. steve needs to take at least 24 milligrams of calcium, 15 milligrams of iron, and 16 milligrams of vitamins. which ordered pairs of values are solutions for the given system inequalities, where x represents the number of spoonfuls of brand a that steve takes and y represents the number of spoonfuls of brand b that steve takes? select all the correct answers.