Answer:
area = Iw
Step-by-step explanation:
area = lw
where
l = length
w = width
Therefore,
The area of the shaded region = area of the big rectangle - area of the small rectangle
Therefore,
area of the big rectangle = (x+10)(2x+5) = 2x² + 5x + 20x + 50 = 2x² + 25x + 50
area of the small rectangle = (x+1)(x+1) = x² + x + x + 1 = x² + 2x + 1
area of the shaded region = 2x² + 25x + 50 - ( x² + 2x + 1)
area of the shaded region = 2x² + 25x + 50 - x² - 2x - 1
area of the shaded region = x² - 23x - 49