Let p represent pounds of apple left.
We have been given that Will makes 2 batches of applesauce that use 4 pounds each. So pounds of apple used in 2 batches of applesauce would be
pounds.
Further we are told that Will makes one batch of apple butter that uses 6 pounds, and he uses 3 pounds to make juice. So pounds of apples used in apple butter and juice would be
pounds.
Total pounds of apples used in all recipes will be
pounds.
We have been given that Will has 20 pounds of apples. So pounds of apples that Will has left would be 20 pounds minus total pounds of used apples.

Therefore, the equation
represents pounds of apples that Will has left.