Let's find the expressions for the length and width of the rectangle. The length (which we will call l) is 2 units less than some undefined number, thus we will use the variable x:
l = x - 2
The width is 4 more than this length:
w = l + 4 = (x - 2) + 4 = x + 2
Now, given that we have the length and width and are looking for the area, we need to multiply these expressions together.
One way to write this would simply be (x + 2)(x - 2). If we wanted to find a different way of writing the area, we could use FOIL to find all terms and get x^2 - 4.
