stacy bought a skateboard at a local sporting goods store. the skateboard was on sale for 10% off the original price. the store then charges 10% sales tax.
a. how does the original price compare to the final price?
b. would the final price be different if the 10% sales tax was added first and then the 10% discount was applied to this new amount?

The original price will be larger than the final price because you would be taxing the discounted price not the original price.

Yes. If you add the sales tax first then the discount wont be on just the product. it would be on the product and the tax with the product. so you have to first get the discounted price from the store and then tax for the county.