A profit is described by P equals 5x plus 8y. What is the profit when x is 4 and y is 6?

1. The equation that is to be made as large as possible is the objective function. 2. Substitute the given values into it one term at a time. 3. Five times 4 is 20. 4. Eight times 6 is 48. 5. Adding the two terms gives 20 plus 48, which is 68. 6. Answering 48 uses only the second term and drops the first one. _Source: Siyavula Mathematics Grade 11 (Everything Maths, CC BY 4.0), Chapter 12: Linear programming_