$40
1) Since Noah has a coupon (30% off) we can write the following
Since Noah has paid $28 after we can write the following equation to find the regular price.
jeans' price = j
j(1-0.3) = 28 We can write the discount of 30% as 0.3
j(0.7) =28 Divide both sides by 0.7
j=28/0.7
j=40
Notice that we have to subtract that percentage (0.3) from 1. To find the factor
2) Hence, the regular price of that pair of jeans is $40