I have some help plzzz

What are the domain and range of f(x)=[1/5]x

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

What is the perimeter of a rectangular building that is 80 feet wide and 140 feet deep?