The equation for developing a production budget is select an option plus select an option minus select an option.

It seems like you're asking for the formula to develop a production budget. The general equation for a production budget is:

Beginning Inventory + Production - Ending Inventory = Sales

Here's a step-by-step breakdown:

1. Beginning Inventory: This is the amount of product you have at the start of the period.

2. Production: This is the amount of product you plan to produce in the period.

3. Ending Inventory: This is the amount of product you plan to have left at the end of the period.

4. Sales: This is the amount of product you plan to sell during the period.

So, to find out how much you need to produce, you would rearrange the equation to:

Production = Sales + Ending Inventory - Beginning Inventory

This tells you that the amount you need to produce is equal to what you plan to sell, plus what you want left over, minus what you already have.