Answer:
If x = $30 is the regular price of a souvenir, then the sale price for each additional souvenir will be 0.3x = 0.3($30) = $9 less than the regular price. Therefore, the sale price of each additional souvenir will be:
Sale price = Regular price - $9
Sale price = $30 - $9
Sale price = $21
Since Carmen purchases 10 souvenirs, she pays the regular price for the first souvenir and the sale price for the remaining 9 souvenirs. Therefore, the total cost for all 10 souvenirs will be:
Total cost = (Regular price for first souvenir) + (Sale price for 9 additional souvenirs)
Total cost = ($30) + ($21 x 9)
Total cost = $30 + $189
Total cost = $219
Therefore, Carmen pays $219 for 10 souvenirs during the sale.
Explanation: