Answer:
First of all, we should know the formula of the are of the rectangle, which is base by height
We should also know the perimeter of a rectangle (and any other figure) is the sum of all its sides, in this case, 4 sides.
Now, we should be able to write the expressions which represent teh area and perimeter of the rectangle as we know the length of each side.
Area: base * height = 12 * (x - 2) = 12x - 24
Perimeter (note each side lenght appears two times, as the rectangles is a regular shape with 4 sides, where the parallel ones have the same lenght):
2 * 12 + 2 * (x-2) = 24 + 2x - 4 = 20 + 3x