Answer:
$4
Explanation:
Discount is a form of consideration in price or amount given to a customer on a sale of goods. It can be deduced from the question that;
The original price of each plant = $x
Number of plants purchased = 20
Price of the number of plants purchased without discount = $20x
Amount paid for the 20 plants with discount = $(20x - 80)
Thus,
The discount on the 20 plants = $80
Discount on each plant =

=

= $4
Discount on each plant = $4
Therefore, each plant was discounted by $4.