Answer:
Explanation:
if he got a 30% discount, that means he paid 70% of the original price.
so 70% of the original price is 280
let x = original price
0.70x = 280
x = 280 / 0.70
x = $ 400 <=== original price
so the discount he received was 30% off of the original price
0.30(400) = $ 120 discount <===
or u could have just taken what he payed and subtracted it from the original price...400 - 280 = $ 120 discount