Six apples and 12 oranges cost $18. if x represents the cost of one apple and y represents the cost of one orange, then the variables can be related using the equation 6x + 12y + 18. Witch variable is the independent variable.

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