Answer: the area of the shaded region is 5x² + 26x + 21
Explanation:
The given figure contains a small rectangle and a large rectangle. The difference between the area of the large rectangle and the small rectangle is the shaded area.
The formula for determining the area of a rectangle is expressed as
Area = length × width.
Area of the large rectangle is
(3x + 6)(2x + 4). Expanding the brackets, it becomes
6x² + 12x + 12x + 24
= 6x² + 24x + 24
Area of the small rectangle is
(x - 3)(x - 1). Expanding the brackets, it becomes
x² + x - 3x + 3
= x² - 2x + 3
Therefore, the area of the shaded region is
6x² + 24x + 24 - (x² - 2x + 3)
= 6x² + 24x + 24 - x² + 2x - 3
= 6x² - x² + 24x + 2x + 24 - 3
= 5x² + 26x + 21