Which problem can be solved using the equation shown? 2.50x-2.00=10.50 will bought several books that cost $2.50 each and received a $2.00 discount on his total bill. if he paid $10.50, how many books did he buy? will bought several books that cost $2.00 each and received a $2.00 discount on his total bill. if he paid $10.50, how many books did he buy? will bought several books that cost $10.50 each and received a $2.00 discount on his total bill. if he paid $2.50, how many books did he buy? will bought several books that cost $10.50 each and received a $2.50 discount on his total bill. if he paid $2.50, how many books did he buy?