gerald owns 90 paperback books. the number of paperback books that gerald owns is 15 less than 3 times the number of hardcover books. how many hardcover books does he own?

Alex is the head photographer for the yearbook and the newspaper. she has a large staff of assistant photographers because they need to take pictures at all of the school events. she knows that some of her photographers have better cameras and can take action shots at sporting events, and that some of them are good at taking candid pictures in the hallways. she sets firm deadlines so she has enough time to look through all of the shots and choose the best ones. she gives her photographers constructive feedback to them improve their pictures. respectful enforcer warlord doormat peacemaker

How do you work out 21.3-8= show your working. plz

Use the rule of 72 to calculate how long it will take for your money to double if its earning 6% in interest. a. 12yrs b. 16yrs c. 36yrs d. 72yrs