Trechelle is buying a sports coat that has a regular price of $90. This coat is on sale with a 20% discount. She knows she needs to pay 8\%8% sales tax on the discounted price. Trechelle thinks to herself 20\%-8\%=12\%20%−8%=12%. She now believes this means she is really only getting a 12% discount, and 12% of $90 is $10.80. She works out the sports coat will cost her $79.20$. Is Trechelle’s reasoning correct or will the sports coat actually cost a different amount?