Answer:
Ms Costco, 17,930.43
Step-by-step explanation:
We want to compare the discounted price to the lower non-discounted price. The least of these will be the better deal.
The price Ms Costco is offered is 10% less than 18795. That is ...
18795 × (1 -10%) = 18795 × 0.90 = 16,915.50
The non-discounted price offered to Ms Deele is 17,050.
This is a higher price than the discounted price of 16,915.50 offered to Ms Costco.
Adding 6% tax to the discounted price, we get ...
16,915.50 × (1 +6%) = 16,915.50 × 1.06 = 17,930.43
The after-tax price of the better deal is 17,930.43.