John has 48 square centimeter tiles he wants to use to create a mosaic. he wants the mosaic to be rectangular with a length that is 2 centimeters longer than the width.

which equation could john solve to find w, the greatest width in centimeters he can use for the mosaic?

w(w – 2) = 48

w(w + 2) = 48
2w(w – 2) = 48
2w(w + 2) = 48

The area (A) of a rectangular figure may be solved by the formula,
                                    A = l x w
where l is length and w is width. 
Given that length is 2 cm longer than the width, it may be expressed as l = w + 2. Then, the area becomes,
                                     (w + 2) x w = 48
Hence, the answer is the second choice. 

Where are the functions?