What is the relationship of length and width?
If W is the width, then W + 6 is the length; length it is 6 centimeters longer than it is wide.
Remember the perimeter is the distance around, what would be the formula? (Drawing a picture may help.)
Area is equal to length times width. Since you do not know either one, try expressing one as a function of the other. (Isolate length or width on one side of the equation.)
David
