An athlete wants to supplement his daily diet with beef and plant proteins. The content of iron, calcium, and vitamins (in milligrams per spoonful) is given in the table: Product Iron Calcium Vitamins
Beef Protein 6 3 2
Plant Protein 2 3 4

Which graph shows the number of spoonfuls of beef protein and plant protein he needs to include in his diet to receive at least 18 milligrams of iron, 21 milligrams of calcium, and 16 milligrams of vitamins?

But in a graph like that