Alex and lara have $21.00 each to spend at a book fair, where all students receive a 35% discount. they both want to purchase a copy of the same book, which normally sells for $28.50 plus 10% sales tax. to check if he has enough to purchase the book, alex takes 35% of $28.50 and subtracts that amount from the normal price. he takes 10% of the discounted selling price and adds it back to find the purchase amount. lara takes 65% of the normal purchase price and then computes 110% of the reduced price. is alex correct? is lara correct? do they have enough money to purchase the book? explain your answer using complete sentences, and show your work.