Final answer:
The equation to represent the constraint is 4x + 8y = 15. Given the pounds of one ingredient, we can find the corresponding pounds of the other ingredient using an equation. For example, when y = 0, x = 3.75.
Step-by-step explanation:
The equation to represent the constraint is 4x + 8y = 15. To complete the table, we need to find the amount of one ingredient Diego could have bought given the other. We can rearrange the equation to solve for x: x = (15 - 8y) / 4. Substitute different values for y into this equation to find the corresponding values for x. For example, when y = 0, x = (15 - 8(0)) / 4 = 15/4 = 3.75. So when Diego buys 0 pounds of walnuts, he could have bought 3.75 pounds of raisins.