The perimeter of the rectangle is
The length is
The width is
The formula to calculate the perimeter of a rectangle is given as
By substituting the values of the length, width, and perimeter above we will get the equation below
To talk about the length y in terms of x, we will make y the subject of the formula in the equation above
Hence,
The length y in terms of x is given as y=12-x
To calculate the possible values of x and the possible values of y
The sum of x and y must give 12 therefore,