Percent increase 18 to 45

Which equation represents the function on the graph?

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm

If you have 12 feet of string and you cut it into equal length of 5 inches each how much string will be left