Answer:
-2x -8
Step-by-step explanation:
The border area will be the difference between pool+border and pool. The area of each rectangle is the product of its dimensions.
(x+3)(x-2) -(x+2)(x+1) = (x^2 +x -6) -(x^2 +3x +2)
= x^2(1 -1) +x(1 -3) +(-6 -2)
= -2x -8 . . . area of border
