Answer:
The first expression to represent the new price of an item after the markdown would be:
new price = d * (1 - 0.70)
This expression uses the original price (d) and multiplies it by (1 - 0.70), which is equal to 0.30. This results in the new price being equal to 30% of the original price.
Another way to write this expression would be:
new price = d - (d * 0.70)
This expression also uses the original price (d) and subtracts from it the product of the original price and 0.70. This also results in the new price being equal to 30% of the original price.
Explanation: