Mike sold half of his comic books and then bought 9 more. he now has 12. how many did he begin with?

The spring the owner of a sporting good store decreases the price of winter gloves from $10 to $8 each increases the price of swimming goggles from $8 to $10 without doing the math you think the percent decrease in the price of the gloves the same as the percent increase of the goggles explain why or why not

One integer is 5 more than another. their product is 104. find the integers

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.